What happens, explains David Broockman, a political scientist at the University of California at Berkeley, is that surveys mistake people with diverse political opinions for people with moderate political opinions. The way it works is that a pollster will ask people for their position on a wide range of issues: marijuana legalization, the war in Iraq, universal health care, gay marriage, taxes, climate change, and so on. The answers will then be coded as to whether they’re left or right. People who have a mix of answers on the left and the right average out to the middle — and so they’re labeled as moderate.

But when you drill down into those individual answers you find a lot of opinions that are well out of the political mainstream.

“A lot of people say we should have a universal health-care system run by the state like the British,” says Broockman. “A lot of people say we should deport all undocumented immigrants immediately with no due process. You’ll often see really draconian measures towards gays and lesbians get 16 to 20 percent support. These people look like moderates but they’re actually quite extreme.”

The result is that voters who hold gentle opinions that are all on the left or the right end up looking a lot more extreme than voters who hold intense opinions that fall all over the political spectrum. … “When we say moderate what we really mean is what corporations want,” Broockman says. “Within both parties there is this tension between what the politicians who get more corporate money and tend to be part of the establishment want — that’s what we tend to call moderate — versus what the Tea Party and more liberal members want.”