Latest idea from the great right-wing looney tunes conspiracy: Liberals have survival guilt.
They believe they are evil and their mothers should have aborted them.
They believe America is evil and that the Native American culture should have prevailed and white people don't belong in America.
It's an interesting theory. And certainly some political rants I've read recently from the liberal side would lend it some force. But I would say there's a bit of pot, kettle, black going on, because conservatives have the same problem with rich folks and guilt over being poor.