Orange County is a county located in the Los Angeles metropolitan area in the U.S. state of California. As of the 2010 census, the population was 3,010,232,^[8] making it the third-most populous county in California, the sixth most populous in the U.S., and more populous than 21 U.S. states.^[11] Although mostly suburban, it is the second most densely populated county in the state, behind San Francisco County.^[12] The county's four most populous cities, Anaheim, Santa Ana (the county seat),^[13] Irvine, and Huntington Beach, each have a population exceeding 200,000. Several cities are on the Pacific coast, including Huntington Beach, Newport Beach, Laguna Beach, Dana Point, and San Clemente.

Orange County is included in the Los Angeles-Long Beach-Anaheim, Metropolitan Statistical Area. It has thirty-four incorporated cities. Older cities like Santa Ana, Anaheim, and Fullerton have traditional downtowns dating back to the 19th century, while newer commercial development or "edge cities" stretch along I-5 between Disneyland and Santa Ana and between South Coast Plaza and the Irvine Business Complex, and cluster at Irvine Spectrum. Northern and Central Orange County, while single-family homes are still prevalent, is relatively more urbanized and dense, while beyond Irvine, the county is relatively less dense, though still contiguous, suburban and not exurban.

The county is a tourist center, with attractions like Disneyland, Knott's Berry Farm, and several popular beaches along its more than 40 miles (64 km) of coastline. Throughout the 20th century and up until 2016, it was known for its political conservatism and for being a bastion of the Republican Party, with a 2005 academic study listing three Orange County cities as among America's 25 most conservative.^[14] However, much due to the county's changing demographics, in 2016, Hillary Clinton became the first Democrat since 1936 to win the county in a presidential election, and in the 2018 midterm elections the Democratic Party gained control of all its Congressional seats.^{[15][16][17][18]} While Republicans retain a majority of the county supervisors and state legislators, the number of registered Democrats surpassed the number of registered Republicans in the county in August 2019.^[19][20] At that point, the number of voters not aligned with a political party increased to comprise 27.4% of the county’s voters.^[21]

Members of the Tongva, Juaneño, and Luiseño Native American groups long inhabited the area. After the 1769 expedition of Gaspar de Portolà, a Spanish expedition led by Junipero Serra named the area Valle de Santa Ana (Valley of Saint Anne). On November 1, 1776, Mission San Juan Capistrano became the area's first permanent European settlement. Among those who came with Portolá were José Manuel Nieto and José Antonio Yorba. Both these men were given land grants—Rancho Los Nietos and Rancho Santiago de Santa Ana, respectively. The Nieto heirs were granted land in 1834. The Nieto ranches were known as Rancho Los Alamitos, Rancho Las Bolsas, and Rancho Los Coyotes. Yorba heirs Bernardo Yorba and Teodosio Yorba were also granted Rancho Cañón de Santa Ana (Santa Ana Canyon Ranch) and Rancho Lomas de Santiago, respectively. Other ranchos in Orange County were granted by the Mexican government during the Mexican period in Alta California.^[22]

A severe drought in the 1860s devastated the prevailing industry, cattle ranching, and much land came into the possession of Richard O'Neill, Sr.,^[23] James Irvine and other land barons. In 1887, silver was discovered in the Santa Ana Mountains, attracting settlers via the Santa Fe and Southern Pacific Railroads.

After several failed attempts in previous sessions, the California legislature passed a bill authorizing the portion of Los Angeles County south of Coyote Creek to hold a referendum on whether to remain part of Los Angeles County or to secede and form a new county to be named “Orange” as directed by the legislature. Such referendum required a 2/3 vote for secession to take place, and subsequently on June 4, 1889, the residents south of Coyote Creek voted 2,509 to 500 in favor of secession. After such referendum, Los Angeles County filed three lawsuits in the courts to stall and stop the secession from occurring, but such attempts were futile. On July 17, 1889, a second referendum was held south of the Coyote Creek to determine if the county seat of the to-be county to be in either Anaheim or Santa Ana, along with an election for every county officer. In the end, Santa Ana defeated Anaheim in such referendum and elected right leaning officers, with some, including one of the primary lobbyists for the creation of the county, Henry W. Head, elected to the Board of Supervisors while being a member of the Ku Klux Klan (even though “...the Klan wasn't even supposed to exist at this time, with Bedford [ Nathan Bedford Forrest, Grand Wizard of the Klan] having officially told the Klan to disband and burn all belongings.”),^[24] with Head’s son, Horace Head, elected as District Attorney of the soon to be county, who was known to, as stated by the OC Weekly, threaten “...any Mexicans who walked in front of their homes with shotguns when not burning crosses on front lawns,” along with Horace Head supporting and defending his fathers affiliation with the Ku Klux Klan. With the referendum taken place, the County of Orange was officially incorporated on August 1, 1889, as prescribed by state law.^[25] Since the date of the incorporation of the county, the only geographical changes to have occurred which affected Orange County was when the County and Los Angeles County agreed to trade land around Coyote Creek to adjust the border of the two counties to conform with city blocks.^[24][26]

The county is said to have been named for the citrus fruit in an attempt to promote immigration by suggesting a semi-tropical paradise – a place where anything could grow.^[27]

Other citrus crops, avocados, and oil extraction were also important to the early economy. Orange County benefited from the July 4, 1904 completion of the Pacific Electric Railway, a trolley connecting Los Angeles with Santa Ana and Newport Beach. The link made Orange County an accessible weekend retreat for celebrities of early Hollywood. It was deemed so significant that Pacific City changed its name to Huntington Beach in honor of Henry E. Huntington, president of the Pacific Electric and nephew of Collis Huntington. Transportation further improved with the completion of the State Route and U.S. Route 101 (now mostly Interstate 5) in the 1920s.

Agriculture, such as that involving the boysenberries made famous by Buena Park native Walter Knott, began to decline after World War II. However, the county's prosperity soared during this time. The completion of Interstate 5 in 1954 helped make Orange County a bedroom community for many who moved to Southern California to work in aerospace and manufacturing. Orange County received a further boost in 1955 with the opening of Disneyland.

In 1969, Yorba Linda-born Orange County native Richard Nixon became the 37th President of the United States.

In the 1980s, Orange County had become the second most populous county in California as the population topped two million for the first time.

In 1994, an investment fund meltdown led to the criminal prosecution of treasurer Robert Citron. The county lost at least $1.5 billion through high-risk investments in bonds. The loss was blamed on derivatives by some media reports.^[28] On December 6, 1994, the County of Orange declared Chapter 9 bankruptcy,^[28] from which it emerged on June 12, 1996.^[29] The Orange County bankruptcy was at the time the largest municipal bankruptcy in U.S. history.^[28]

In recent years, land use conflicts have arisen between established areas in the north and less developed areas in the south. These conflicts have regarded issues such as construction of new toll roads and the repurposing of a decommissioned air base. El Toro Marine Corps Air Station was designated by a voter measure in 1994 to be developed into an international airport to complement the existing John Wayne Airport. But subsequent voter initiatives and court actions have caused the airport plan to be permanently shelved. Instead, it became the Orange County Great Park.^[30]

According to the U.S. Census Bureau, the county has a total area of 948 square miles (2,460 km2), of which 791 square miles (2,050 km2) is land and 157 square miles (410 km2) (16.6%) is water.^[31] It is the smallest county by area in Southern California. The average annual temperature is about 68 °F (20 °C).

Orange County is bordered on the southwest by the Pacific Ocean, on the north by Los Angeles County, on the northeast by San Bernardino County, on the east by Riverside County, and on the southeast by San Diego County.

The northwestern part of the county lies on the coastal plain of the Los Angeles Basin, while the southeastern end rises into the foothills of the Santa Ana Mountains. Most of Orange County's population reside in one of two shallow coastal valleys that lie in the basin, the Santa Ana Valley and the Saddleback Valley. The Santa Ana Mountains lie within the eastern boundaries of the county and of the Cleveland National Forest. The high point is Santiago Peak (5,689 feet (1,734 m)^[32]), about 20 mi (32 km) east of Santa Ana. Santiago Peak and nearby Modjeska Peak, just 200 feet (60 m) shorter, form a ridge known as Saddleback, visible from almost everywhere in the county. The Peralta Hills extend westward from the Santa Ana Mountains through the communities of Anaheim Hills, Orange, and ending in Olive. The Loma Ridge is another prominent feature, running parallel to the Santa Ana Mountains through the central part of the county, separated from the taller mountains to the east by Santiago Canyon.

The Santa Ana River is the county's principal watercourse, flowing through the middle of the county from northeast to southwest. Its major tributary to the south and east is Santiago Creek. Other watercourses within the county include Aliso Creek, San Juan Creek, and Horsethief Creek. In the North, the San Gabriel River also briefly crosses into Orange County and exits into the Pacific on the Los Angeles-Orange County line between the cities of Long Beach and Seal Beach. Laguna Beach is home to the county's only natural lakes, Laguna Lakes, which are formed by water rising up against an underground fault.

Orange County is sometimes figuratively divided into "North Orange County" and "South Orange County". Sometimes, in addition, reference is made to an "Orange Coast" area, some or all of the North and South County cities lining the coast. There are significant political, demographic, economic, and cultural distinctions between North and South Orange County.^[33]

North Orange County — including cities like Anaheim, Fullerton, and Santa Ana is, overall, the older, more ethnically diverse and more densely built-up area closer to Los Angeles, having greater populations of people of color, younger populations, greater percentages of renters, lower median incomes, higher rates of unemployment, and greater proportions of voters registered as Democrats than Republicans. Santa Ana is in fact the fifth most densely populated city in the U.S. of over 200,000 people in size. There are important exceptions to this characterization of North County, such as affluent Anaheim Hills and Villa Park.^[33]

South Orange County is, overall, more residential, more affluent, with a mostly white population, and was more recently developed. Irvine is an exception to these general South County traits due to its ethnic diversity and as a major employment center. Where South Orange County begins is defined slightly differently according to the source, nearly always including Newport Beach, Irvine^[34] and cities to their southeast including Laguna Beach, Mission Viejo, and San Clemente. Sometimes Costa Mesa is included in South County,^[35] but sometimes the dividing line is defined as the southwest-to-northeast path of the Costa Mesa Freeway,^[36] thus excluding the city of Costa Mesa.

There is no formal geographic division between North and South County, although there is a northeast to southwest topographic transition from elevated areas inland to the lower coastal band, and, perpendicular to that gradient, the Santa Ana River roughly divides the county into northwestern and southeastern sectors.

Older cities like Santa Ana, Anaheim, and Fullerton have traditional downtowns dating back to the 19th century, with Downtown Santa Ana being the home of the county, state and federal institutions. However, far more commercial activity is concentrated in clusters of newer commercial development are found in the county's edge cities, the three largest being

A contiguous strip of commercial development (an edge city) stretches from Disneyland through to MainPlace Mall along the I-5 Santa Ana Freeway,^{[37][38][39][40][41]} straddling the city limits of Anaheim, Garden Grove, Orange, and Santa Ana, and in fact stretching between the original downtowns of those four cities.

Entertainment and cultural facilities include Disneyland Resort, Angel Stadium, Christ Cathedral (formerly Crystal Cathedral), City National Grove of Anaheim - a live concert venue, Discovery Cube Orange County, the Honda Center - home to the Anaheim Ducks of the NHL (National Hockey League), and the Anaheim Convention Center. Health care facilities include CHOC (Children's Hospital of Orange County), Kaiser Permanente Health Pavilion (Anaheim), St. Joseph Hospital (Orange), and the UCI Medical Center.

Retail complexes include Anaheim GardenWalk, Anaheim Marketplace (claiming to be the largest indoor swap meet in Orange County with more than 200 vendors), MainPlace Mall, Orange Town & Country, and The Outlets at Orange, originally a mall named "The City" which was the centerpiece of a planned, 1970s mixed-use development by the same name. There is commercial strip-style development including big box retailers along West Chapman Avenue in Orange (Marshalls, Ralphs), along Harbor Boulevard in Garden Grove (Burlington, Ross Dress for Less), and around Harbor Blvd. and Chapman Ave. in Anaheim (Target).

Major hotels line Harbor Boulevard from Disneyland south to Garden Grove: Grand Legacy at the Park, Hilton, Marriott, Courtyard, DoubleTree Suites, Hampton Inn, Hilton Garden Inn, Homewood Suites, Embassy Suites, Residence Inn, Hyatt Regency, Marriott Suites, Sheraton, and the Great Wolf Lodge. The Orange County Transit Authority studied the corridor as the possible route for a streetcar, a proposal that was dropped in 2018 due to opposition from Anaheim and other city governments.^[42]

In addition to suburban-style apartment complexes, Anaheim's Platinum Triangle is undergoing transformation from a low-density commercial and industrial zone into a more urban environment with high-density housing, commercial office towers, and retail space. Anaheim envisions it as a "downtown for Orange County".^[43] The 820 acres (330 ha) area undergoing this large-scale redevelopment includes the city's two major sports venues, the Honda Center and Angel Stadium of Anaheim.^[44]

Los Angeles County (north), San Diego County (south), Riverside County (east), San Bernardino County (northeast).

The 2010 United States Census reported that Orange County had a population of 3,010,232. The racial makeup of Orange County was 1,830,758 (60.8%) White (44.0% non-Hispanic white), 50,744 (1.7%) African American, 18,132 (0.6%) Native American, 537,804 (17.9%) Asian, 9,354 (0.3%) Pacific Islander, 435,641 (14.5%) from other races, and 127,799 (4.2%) from two or more races. Hispanic or Latino of any race were 1,012,973 persons (33.7%).^[59]

The Hispanic and Latino population is predominantly of Mexican origin; this group accounts for 28.5% of the county's population, followed by Salvadorans (0.8%), Guatemalans (0.5%), Puerto Ricans (0.4%), Cubans (0.3%), Colombians (0.3%), and Peruvians (0.3%).^[60] Santa Ana with its population reportedly 75 percent Hispanic/Latino, is among the most Hispanic/Latino percentage cities in both California and the U.S., esp. of Mexican-American descent.^[61] See also Logan Park (Santa Ana), the city's largest and oldest barrio.

Among the Asian population, 6.1% are Vietnamese, followed by Koreans (2.9%), Chinese (2.7%), Filipinos (2.4%), Indians (1.4%), Japanese (1.1%), Cambodians (0.2%) Pakistanis (0.2%), Thais (0.1%), Indonesians (0.1%), and Laotians (0.1%).^[60] According to KPCC in 2014, Orange County has the largest proportion of Asian Americans in Southern California, where one in five residents are Asian American.^[62] There is also a significant Muslim population in the county.^[63]

As of the census^[64] of 2000, there were 2,846,289 people, 935,287 households, and 667,794 families residing in the county, making Orange County the second most populous county in California. The population density was 1,392/km2 (3,606/sq mi). There were 969,484 housing units at an average density of 474/km2 (1,228/sq mi). The racial makeup of the county was 64.8% White, 13.6% Asian, 1.7% African American, 0.7% Native American, 0.3% Pacific Islander, 14.8% from other races, and 4.1% from two or more races. 30.8% are Hispanic or Latino of any race. 8.9% were of German, 6.9% English and 6.0% Irish ancestry according to Census 2000. 58.6% spoke only English at home; 25.3% spoke Spanish, 4.7% Vietnamese, 1.9% Korean, 1.5% Chinese (Cantonese or Mandarin) and 1.2% Tagalog.

In 1990, still according to the census^[65] there were 2,410,556 people residing in the county. The racial makeup of the county was 78.6% White, 10.3% Asian or Pacific Islander, 1.8% African American, 0.5% Native American, and 8.8% from other races. 23.4% were Hispanic or Latino of any race.

Out of 935,287 households, 37.0% had children under the age of 18 living with them, 55.9% married couples were living together, 10.7% had a female householder with no husband present, and 28.6% were non-families. 21.1% of all households were made up of individuals and 7.2% had someone living alone who was 65 years of age or older. The average household size was 3.00 and the average family size was 3.48.

Ethnic change has been transforming the population. By 2009, nearly 45 percent of the residents spoke a language other than English at home. Whites now comprise only 45 percent of the population, while the numbers of Hispanics grow steadily, along with Vietnamese, Korean and Chinese families. The percentage of foreign-born residents jumped to 30 percent in 2008 from 6 percent in 1970. The mayor of Irvine, Sukhee Kang, was born in Korea, making him the first Korean-American to run a major American city. “We have 35 languages spoken in our city,” Kang observed.^[66] The population is diverse age-wise, with 27.0% under the age of 18, 9.4% from 18 to 24, 33.2% from 25 to 44, 20.6% from 45 to 64, and 9.9% 65 years of age or older. The median age is 33 years. For every 100 females, there were 99.0 males. For every 100 females age 18 and over, there were 96.7 males.

The median income for a household in the county was $61,899, and the median income for a family was $75,700 (these figures had risen to $71,601 and $81,260 respectively as of a 2007 estimate^[67]). Males had a median income of $45,059 versus $34,026 for females. The per capita income for the county was $25,826. About 7.0% of families and 10.3% of the population were below the poverty line, including 13.2% of those under age 18 and 6.2% of those age 65 or over.

Residents of Orange County are known as "Orange Countians".^[68]

Orange County is the base for several religious organizations:

Orange County is a charter county of California; its seat is Santa Ana.

The elected offices of the county government consist of the five-member Board of Supervisors, Assessor, Auditor-Controller, Clerk-Recorder, District Attorney-Public Administrator, Sheriff-Coroner, and Treasurer-Tax Collector. Except for the Board of Supervisors, each of these elected officers are elected by the voters of the entire county and oversee their own County departments.^[77]

As of January 2019, the six countywide elected officers are:^[77][78]

A seventh countywide elected officer, the County Superintendent of Schools (jointly with an independently-elected County Board of Education) oversees the independent Orange County Department of Education.^[80]

Each of the five members of the Board of Supervisors is elected from a regional district, and together, the board oversees the activities of the county's agencies and departments and sets policy on development, public improvements, and county services. At the beginning of each calendar year, the Supervisors select a Chair and Vice Chair amongst themselves. The Chair presides over board meetings, and the Vice Chair presides when the Chair is not present. The Board appoints the Clerk of the Board of Supervisors, the County Counsel, the Performance Audit Director, and the Director of the Office of Independent Review. The Board also appoints the County Executive Officer to act as the chief administrative officer of the county and the manager of all agencies and departments not under the sole jurisdiction of an elected county official nor the sole jurisdiction of one of the four aforementioned officers appointed by the Board.^[81]

As of March 2019, the members of the Orange County Board of Supervisors are:^[77][78][81]

The County Department of Education is wholly separate from the County government and is jointly overseen by the elected County Superintendent of Schools and the five-member Orange County Board of Education, whose trustees are popularly elected from five separate trustee areas.^[80]

As of January 2019, the six elected officials overseeing the Orange County Department of Education are:^[78][82]

On July 12, 2010, it was revealed that former Sheriff Mike Carona received over $215,000 in pension checks in 2009, despite his felony conviction.^[83] A 2005 state law denied a public pension to public officials convicted of wrongdoing in office, however, that law only applied to benefits accrued after December 2005. Carona became eligible for his pension at age 50, and is also entitled, by law, to medical and dental benefits.^[84][85] It was noted that the county's retirement system faces a massive shortfall totaling $3.7 billion unfunded liabilities, and Carona was one of approximately 400 retired Orange County public servants who received more than $100,000 in benefits in 2009.^[86] Also on the list of those receiving extra-large pension checks is former treasurer-tax collector Robert Citron, whose investments, which were made while consulting psychics and astrologers, led Orange County into bankruptcy in 1994.^[87]

Citron, a Democrat, funneled billions of public dollars into questionable investments, and at first the returns were high and cities, schools and special districts borrowed millions to join in the investments. But the strategy backfired, and Citron's investment pool lost $1.64 billion. Nearly $200 million had to be slashed from the county budget and more than 1,000 jobs were cut. The county was forced to borrow $1 billion.^[88]

The California Foundation for Fiscal Responsibility filed a lawsuit against the pension system to get the list. The agency had claimed that pensioner privacy would be compromised by the release. A judge approved the release and the documents were released late June 2010. The release of the documents has reopened debate on the pension plan for retired public safety workers approved in 2001 when Carona was sheriff.^[89]

Called "3 percent at 50," it lets deputies retire at age 50 with 3 percent of their highest year's pay for every year of service. Before it was approved and applied retroactively, employees received 2 percent.^[90] "It was right after Sept. 11," said Orange County Supervisor John Moorlach. "All of a sudden, public safety people became elevated to god status. The Board of Supervisors were tripping over themselves to make the motion." He called it "one of the biggest shifts of money from the private sector to the public sector." Moorlach, who was not on the board when the plan was approved, led the fight to repeal the benefit. A lawsuit, which said the benefit should go before voters, was rejected in Los Angeles County Superior Court in 2009 and is now under appeal.^[89] Carona opposed the lawsuit when it was filed, likening its filing to a "nuclear bomb" for deputies.

Throughout the 20th century and up until 2016, it was known for its political conservatism and for being a bastion for the Republican Party, with a 2005 academic study listing three Orange County cities as among America's 25 most conservative.^[91] However, the county's changing demographics have resulted in a shift in political alignments. In 2016, Hillary Clinton became the first Democrat since 1936 to carry Orange County in a presidential election and in the 2018 midterm elections the Democratic Party gained control of every Congressional seat in the county.^{[15][16][17][18]} Although Democrats control all congressional districts in Orange County, Republicans maintained a lead in voter registration numbers, although it shrunk to less than a percentage point as of February 10, 2019,^[92] as compared with over 10% on February 10, 2013.^[93] The number of registered Democrats surpassed the number of registered Republicans in the county in August 2019. As the number of Democrats increased, the number of voters not aligned with a political party increased to comprise 27.4% of the county’s voters in 2019.^[21] Republicans hold a 4-1 majority on the county Board of Supervisors. Seven out of the 12 state legislators from Orange County are also Republicans.

Orange County has long been known as a Republican stronghold and has consistently sent Republican representatives to the state and federal legislatures — so strongly so, that Ronald Reagan described it as the place that "all the good Republicans go to die."^[15] Republican majorities in Orange County helped deliver California's electoral votes to Republican nominees Richard Nixon in 1960, 1968 and 1972, Gerald Ford in 1976, Reagan in 1980 and 1984, and George H. W. Bush in 1988. As a measure of how Republican Orange County was during this period, it was one of only five counties in the state that voted for Barry Goldwater in 1964.

In 1936 Orange County gave Franklin D. Roosevelt a majority of its presidential vote. The Republican nominee won Orange County in the next 19 presidential elections, until Hillary Clinton won the county with a majority in 2016.^[94][95]

The Republican margin began to narrow in the 1990s and 2000s as the state trended Democratic, until, in the 2018 midterm elections, the Democratic Party gained control of all seven Congressional districts in the county, including all four districts anchored in the county.^[96] This prompted media outlets to declare Orange County's Republican leanings "dead", with the Los Angeles Times running an op-ed titled, "An obituary to old Orange County, dead at age 129."^{[15][16][17][18][97]}

For the 116th United States Congress in the United States House of Representatives, Orange County is split between seven congressional districts:^[100]

The 39th, 45th, 46th, and 48th districts are all centered in Orange County. The 38th and 47th have their population centers in Los Angeles County, while the 49th is primarily San Diego County-based.

In the California State Senate, Orange County is split into 5 districts:^[101]

In the California State Assembly, Orange County is split into 7 districts:^[101]

According to the California Secretary of State, as of February 10, 2019, Orange County has 1,591,543 registered voters. Of these, 34% (541,711) are registered Republicans, and 33.3% (529,651) are registered Democrats. An additional 28.5% (453,343) declined to state a political party.^[92]

Orange County has produced such notable Republicans as President Richard Nixon (born in Yorba Linda and lived in Fullerton and San Clemente), U.S. Senator John F. Seymour (previously mayor of Anaheim, California), and U.S. Senator Thomas Kuchel (of Anaheim). Former Congressman Christopher Cox (of Newport Beach), a White House counsel for President Reagan, is also a former chairman of the U.S. Securities and Exchange Commission. Orange County was also home to former Republican Congressman John G. Schmitz, a presidential candidate in 1972 from the ultra-conservative American Independent Party and the father of Mary Kay Letourneau. In 1996, Curt Pringle (later mayor of Anaheim) became the first Republican Speaker of the California State Assembly in decades.

While the growth of the county's Hispanic and Asian populations in recent decades has significantly influenced Orange County's culture, its conservative reputation has remained largely intact. Partisan voter registration patterns of Hispanics, Asians and other ethnic minorities in the county have tended to reflect the surrounding demographics, with resultant Republican majorities in all but the central portion of the county. When Loretta Sanchez, a Blue Dog Democrat, defeated veteran Republican Bob Dornan in 1996, she was continuing a trend of Democratic representation of that district that had been interrupted by Dornan's 1984 upset of former Congressman Jerry Patterson. Until 1992, Sanchez herself was a moderate Republican, and she is viewed as somewhat more moderate than other Democrats from Southern California.

Republicans have responded to the influx of nonwhite immigrants by making more explicit efforts to court the Hispanic and Asian vote. In 2004, George W. Bush captured 60% of the county's vote, up from 56% in 2000 despite a higher Democratic popular vote statewide. Although Barbara Boxer won statewide, and fared better in Orange County than she did in 1998, Republican Bill Jones defeated her in the county, 51% to 43%. While the 39% that John Kerry received is higher than the percentage Bill Clinton won in 1992 or 1996, the percentage of the vote George W. Bush received in 2004 (60%) is the highest any presidential candidate has received since 1988, showing a still-dominant GOP presence in the county. In 2006, Senator Dianne Feinstein won 45% of the vote in the county, the best showing of a Democrat in a Senate race in over four decades, but Orange was nevertheless the only Coastal California county to vote for her Republican opponent, Dick Mountjoy.

The county is featured prominently in Lisa McGirr's book Suburban Warriors: The Origins of the New American Right. She argues that its conservative political orientation in the 20th century owed much to its settlement by farmers from the Great Plains, who reacted strongly to communist sympathies, the civil rights movement, and the turmoil of the 1960s in nearby Los Angeles — across the "Orange Curtain".

In the 1970s and 1980s, Orange County was one of California's leading Republican voting blocs and a subculture of residents with "Middle American" values that emphasized capitalist religious morality in contrast to West coast liberalism.

Orange County has many Republican voters from culturally conservative Asian-American, Middle Eastern and Latino immigrant groups. The large Vietnamese-American communities in Garden Grove and Westminster are predominantly Republican; Vietnamese Americans registered Republicans outnumber those registered as Democrats, 55% to 22% as of 2007, while as of 2017 that figure is 42% to 36%. Republican Assemblyman Van Tran was the first Vietnamese-American elected to a state legislature and joined with Texan Hubert Vo as the highest-ranking elected Vietnamese-American in the United States until the 2008 election of Joseph Cao in Louisiana's 2nd congressional district. In the 2007 special election for the vacant county supervisor seat following Democrat Lou Correa's election to the state senate, two Vietnamese-American Republican candidates topped the list of 10 candidates, separated from each other by only seven votes, making the Orange County Board of Supervisors entirely Republican; Correa is first of only two Democrats to have served on the Board since 1987 and only the fifth since 1963.

Even with the Democratic sweep of Orange County's congressional seats in 2018, as well as a steady trend of Democratic gains in voter registration, the county remains very Republican downballot. In much of the county, the district's congressperson is the only elected Democrat above the county level, and in some cases the only elected Democrat above the municipal level. Generally, larger cities–those with a population over 100,000, such as Anaheim, Santa Ana, and Irvine - feature a registration advantage for Democrats, while the other municipalities still have a Republican voter registration advantage. This is especially true in Newport Beach, Yorba Linda, and Villa Park, the three cities where the Republican advantage is largest . As of February 10, 2019, the only exceptions to the former are Huntington Beach and Orange, while exceptions to the latter include Buena Park, Laguna Beach and Stanton.^[92]