Reagan opposed the Civil Rights Act of 1964, opposed the Voting Rights Act of 1965 (calling it "humiliating to the South"), and ran for governor of California in 1966 promising to wipe the Fair Housing Act off the books. "If an individual wants to discriminate against Negroes or others in selling or renting his house," he said, "he has a right to do so." After the Republican convention in 1980, Reagan travelled to the county fair in Neshoba, Mississippi, where, in 1964, three Freedom Riders had been slain by the Ku Klux Klan. Before an all-white crowd of tens of thousands, Reagan declared: "I believe in states' rights".
As president, Reagan aligned his justice department on the side of segregation, supporting the fundamentalist Bob Jones University in its case seeking federal funds for institutions that discriminate on the basis of race. In 1983, when the supreme court decided against Bob Jones, Reagan, under fire from his right in the aftermath, gutted the Civil Rights Commission.
Indeed, though one of the only nice things one can say about George W. Bush is that he's made some kind of effort to detoxify the Republicans' image in minority communities, it's still the case that he's followed Ronald Reagan's lead in having the Civil Rights Division of the Justice Department stop enforcing laws barring discrimination against racial minorities. We should probably understand that as part-and-parcel of the Bush administration's broad-based effort to stop enforcing all kinds of regulations that might burden business (indeed, as I pointed out once in a Cato Unbound essay, when libertarianism was actually tried in the form of the Goldwater campaign it turned out that the main constituency for it was among hard-core white supremacists) rather than racism as such.