The New Yorker cover controversy revealed the humorless side of the Obama campaign and produced a good laugh from Jon Stewart among others.

But the cover also raises another interesting question. What religion do Americans think Obama practices? And do those views--accurate or not--shape their preferences about his candidacy?

Pew Research shed some light on these questions on Tuesday with the release of new polling data.

The Pew study reveals nearly four out 10 (37 percent) are off in one way or another when it comes to knowing Obama’s religion. That 37 percent breaks down this way: 12 percent think he’s Muslim, 10 percent say they “don’t know and have heard different things,” and 15 percent answer they “don’t know and haven’t heard enough.” Given all the controversy about his church and his pastor earlier in the year, the lack of knowledge about his religion says a lot about the average American attention span on this issue.

The Pew survey also suggests the notion that Obama is Muslim hurts him among Democrats, but not Republicans. For example, of the Democrats who think he’s a Christian, Obama draws 90 percent support. But among those who say he is a Muslim, he only garners 62 percent--a gap of 28 points.

Views of Obama’s religion--accurate or not--have no impact among Republicans. He draws 10 percent support from Republicans who think he’s a Christian and 10 percent from those who think he’s Muslim.