
Persecution is a core part of Christian identity in that a great many Christians seem to believe that they are being persecuted for their beliefs in spite of ample evidence to the contrary. I can think of at least two explanations for this persecution complex, and they are not mutually exclusive.
First, the Christian bible makes a strong case that Jews living in biblical times were persecuted. And we all know what is supposed to have happened to Jesus himself (assuming that there ever was such a person). From the earliest beginnings of Christianity, persecution was a key part of the experience. It makes sense that this would continue to be part of their identity.
Second, I suspect that many Americans Christians are simply engaging in projection when they claim persecution. That is, they themselves seek to oppress anyone who disagrees with their religion and so they project this tendency onto everyone else. By accusing others of persecution, they minimize awareness of the implications of their own behavior.
When I look at atheism in the U.S., I see some similarities. Survey after survey reveals that we are the most hated minority group in America. This is nothing new. One could easily argue that we share with Christians the feature of having persecution as a key part of our earliest experience. And even though the notion of projection does not seem to fit us particularly well, we should remain vigilant to the possibility.