http://politicalbetting.com/wp-content/uploads/2007/02/USA%20Today%20poll.GIF
Is this real?
Is it really religious bias, or is it just human nature? Of course you'll want to elect someone who has values similar to your own. What the poll fails to show is
why someone wouldn't vote for a particular candidate; hell, Bill Clinton was a terrific president, but there are those who wouldn't vote for him due to his issues with marital unfaithfulness, or Robert Byrd for being a former KKK member, or Patrick Kennedy for having a drug problem.
"Well-qualified" and "well-liked", unfortunately, don't really go hand-in-hand in American politics anymore. People will jump onboard with candidates with fantastic stories or a lot of hype (see: Hillary Clinton, Barack Obama) but ignore those who are genuinely qualified for the job (see: Evan Bayh).
People will nitpick candidates and politicians for the most stupid reasons. That's a fact of life. However, the reason I typically don't give polls too much credit is because of the information that the poll doesn't offer or didn't ask. It could show that people would oppose a Catholic president simply because he is Catholic, or it could show that they oppose him because some of his Catholic views may play too big a role in his politics. In other words, what's really being looked at here: is it the people's religious bias, or the politician's religious bias? I'm willing to bet money that it's a fair mix of both.
And what exactly does "well-qualified" mean? A Harvard law degree, six years in the state legislature, and twelve years or so in Congress, but someone who is known to be a religious advocate? Someone who can keep an open mind and not let his religious beliefs or racial affiliations influence his decisions to the point of favoritism, but has little political experience?