Orange County has long been known as a Republican stronghold and has consistently sent Republican representatives to the state and federal legislatures. Republican majorities in Orange County helped deliver

California's electoral votes to Republican presidential candidates Richard Nixon (1960, 1968 and 1972), Gerald Ford (1976), Ronald Reagan (1980 and 1984) and George H. W. Bush (1988). Orange County has not voted for a Democratic presidential candidate since Franklin D. Roosevelt's 1936 landslide re-election for a second term. Although Democrats have made inroads in the northern end of the county since the mid-1980s, Orange County politics are still dominated by Republicans. Five of the county's six U.S. Representatives, four of its five State Senators and seven of its nine State Assembly members are Republicans, as are four of the five members of the County Board of Supervisors.
According to the Orange County Registrar of Voters, as of December 26, 2006, Orange County had 1,501,843 registered voters. Of these registered voters, 47.78% (717,546) are registered Republicans, and 30.08% (451,706) are registered Democrats, giving the Republicans a registration advantage of 17.7% (265840) – or over a quarter of a million voters. An additional 18.19% (273,215) declined to state a political party, and the remaining 3.95% (59,376) are registered with minor political parties.
Orange County has produced such notable Republicans as President Richard Nixon (born in Yorba Linda and lived in San Clemente), U.S. Senator John F. Seymour (previously mayor of Anaheim), and U.S. Senator Thomas Kuchel (of Anaheim). Former Congressman Chris Cox (of Newport Beach), a White House counsel for President Ronald Reagan, is currently 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 (currently mayor of Anaheim) became the first Republican-elected 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 the culture of Orange County, 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 Democrat Loretta Sanchez defeated veteran Republican Robert K. Dornan in the congressional contest of 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 Republican, and she is viewed as having moderate or even conservative positions on many issues.
Republicans have responded to the influx of ethnic 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 compared with the 2000 election. 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%. And while the 39% that John Kerry received is higher than the percentage Bill Clinton won in both 1992 and 1996, the percentage of the vote George W. Bush received in 2004 (60% of the vote) is the highest any presidential candidate has received since 1988, showing a still-dominant GOP presence in the county. Democratic strength is concentrated in the communities of Santa Ana, Laguna Beach and Laguna Woods.
The county features prominently in the book Suburban Warriors: The Origins of the New American Right by Lisa McGirr. She argues that the county's conservative political orientation in the 20th century owed much to its settlement by Midwestern transplants, 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 sub-culture of residents to hold "Middle American" values that emphasized a capitalist religious morality in contrast to West coast progressive liberalism that well existed there.
Political jokes spoke of Orange County as a "white" racist bastion, where their city councils alleged to have ties to the Ku Klux Klan and Neo-Nazis, though they are mean-spirited rumors meant to generate controversy on the county's attitudes on the rising percentage of minoritiy groups moving into formerly homogeneous suburban communities.
Santa Ana has a high portion of Republican voters from culturally conservative Asian-American, Middle Eastern and Latino immigrants, many came as refugees from wars and dictatorships, are strongly loyal to policies of the Republican party to defeat communism and radical Islamic terrorism. High numbers of Vietnamese-Americans in Garden Grove and Westminster are also Republican loyalists for the party's anti-communist policies. Republican Assemblyman Van Tran was elected to become the first Vietnamese-American to serve in a state legislature and is tied with Texan Hubert Vo as the highest-ranking elected Vietnamese-American in the United States.