What is "Bigotry?"

Todd Zywicki cites a study suggesting that "53% of professors have an unfavorable view of Evangelical Christians," and describes this as evidence (standing all on its own) of "bigotry."

In defending his use of that term, he says the following:

Some readers have taken issue with my use of the term "bigotry." I used that term to try to capture the flavor of the response that Rick Hills heard in his friend's remark--"the academic’s irrational fear of, or intense discomfort around, theist and, in particular, Christian, beliefs." The flavor of the remark is that the friend had a negative prejudice against Christians such that he or she was surprised to learn that the person in question was a Christian. This is functionally no different from meeting someone who is inconsistent with one's negative stereotypical prejudices of a racial or ethnic group. I think the correct word to apply to that prejudice is "bigotry," but if there is a different word, then please suggest the correct word. I think that the term must be freighted with greater normative implications than I intended, as I intended it to be used descriptively, not normatively.

A question for readers: what is bigotry?

I tend to think that for a negative opinion of a group to be appropriately described as "bigotry" or "prejudice," (either of which ought to be understood as an attitude roughly equivalent to racism, but without the race) it must be based on false beliefs about that group -- either a false belief about various facts associated with the group (what Kwame Anthony Appiah called, in the race context, "extrinsic racism,") or about some inherent moral qualities of the group (e.g. "gays are just evil," what Appiah called "intrinsic racism"). Or, I suppose, it could be based on no facts at all, just a sort of random disliking.

If that's so, then Zywicki's use of the term "bigotry" seems totally unwarranted. For there are many perfectly true reasons to legitimately have a negative opinion of evangelical Christians -- like the prevalence of theologically-sanctioned sexism, the attempts to get creationism taught in schools, the anti-abortion campaigning, and in general the right-wing political influence. And surely there's nothing "bigoted" about having a negative opinion of your political opponents because they're your political opponents. (I happen to have a negative opinion of Republicans. That doesn't make me a bigot.)

Because "bigotry" is a serious charge, the burden of proof ought to be on the accuser. Some kinds of belief, of course, themselves constitute prima facie evidence of bigotry. Those who hold a negative attitude toward, e.g., blacks, women, and Jews, for example, are highly likely to be bigots, because there are no known true reasons to hold a negative opinion of those groups, and many known false reasons that infect our culture. But for groups that aren't the victims of a legacy of historical discrimination, and for which there are plenty of reasons for warranted dislike, it requires more than just statistical evidence that people dislike the group to show that there's "bigotry" at work.