Long, but worth the read:
VICIOUS STEREOTYPES IN POLITE SOCIETY: One of the less attractive patterns in human behavior is our tendency to stereotype those with whom we disagree, those whose interests conflict with our own, or those who are simply different from ourselves. Such stereotypes create and reinforce prejudice, and they distort our politics, our policy debates, and our constitutional debates. These evils are of course well known; they are an important part of racism, sexism, and discrimination against lesbians and gays. But we do not appear to have generalized the lessons.