In short, for a crucially large number of Southern whites, segregation is not as important as any one or a combination of the following: economic profit, political power, good government, an absence of violence, food, recreation, an education, keeping a job.
Furthermore, there is also the powerful force of conformity, both to society at large and to close friends and associates. Conformity is a favorite target of intellectual disdain; few liberals will confess that it is not conformity in the abstract which they abhor, but conformity to certain values which they find reprehensible. Liberals would be delighted, for instance, to have conformity to the principle of free speech. And there is a world of difference between conformity to racism and conformity to the idea of equality. The tendency of people to seek security in the approval of their peers and superiors can be used as a great moral weapon as well as a divisive tool.
– from the chapter “Is the Southern White Unfathomable?” in Howard Zinn’s The Southern Mystique, published in 1964