The “Catholic vote” must refer specifically to the “Observant Catholic vote,” or it’s a meaningless demographic.
First, Catholics differ from Protestants in their fear of apostasy. Protestants often covert or change churches; Catholics rarely do. This is why you hear about lapsed Catholics, but never lapsed Methodists. The point here is that lapsed Catholics, those who never go to Mass, identify themselves as Catholics and always will, but pay no attention to the precepts of the Church. They will always be a part of the “Catholic vote” on any survey or poll, unless the poll differentiates. Most don’t.
Second, you have the cafeteria Catholic segment. Some go to Mass only on Easter and Christmas, while others go to Mass more or less regularly. Because like Protestants, they feel they can pick and choose among matters of faith, they are very hard to pin down. Many are strongly pro-life, but the question is how they balance life against other issues. Note that in response to Pelosi and Biden, over a hundred American bishops have now stated that life is more important than all other issues, although none has endorsed a ticket. These statements may swing many cafeteria Catholics to McCain and Palin.
Remove these two groups from the Catholic demographic, and you are left with the observant Catholics. Note that observant doesn’t merely mean they go to Mass regularly. Observant means that they take their faith seriously, and follow the precepts of the Church. This is perhaps the strongest pro-life group in the United States, and tends to be socially conservative in general.
Two things are going to swing the votes more than we would see in most elections: The bishops’ statements in response to Pelosi and Biden, and the Born Alive Infant Protection Act that Obama refused to vote for. McCain’s support of federal monies for stem-cell research hurt his standing among pro-life Cathoics to some extent, but putting Palin on the ticket seems to have outweighed that, and McCain’s stance on federal money for stem-cell research pales next to Obama’s refusal to support the Born Alive Infant Protection Act as a pro-life issue.
Note, however, that even if only the observant Catholics vote Republican, that’s a significant demographic. There are 67 million Catholics in the United States. If observant Catholics only account for 25% of the entire Catholic population, that’s 16.25 million votes.
(There are other problems with treating the self-identification “Catholic” on polls and surveys as a voting block. First, there is the intersection between Hispanic voters and Catholic voters. Hispanics have a whole set of issues that aren’t necessarily Catholic issues, and these will affect how they vote. Second, you have the historical effect in play with ethnic Catholics that aren’t really ethnic at all anymore, but tend to vote the same way their parents and grandparents, etc., did. These groups tend to be geographically as well as ethnically defined, such as Irish Catholics in MA, Italian Catholics in Philly or NYC, etc., and nearly all are urban.)
Keeping all these problems in mind, there are these poll results. Zogby reports that 54% of Catholics in general are intending to vote McCain. Another Pew poll that differentiates between lapsed and attending (non-lapsed, since this would include cafeteria Catholics who attend Mass and observant Catholics) Catholics reports an even split for McCain and Obama among lapsed Catholics, and a 52-36 McCain advantage among Catholics who attend Mass (non-lapsed).
Oddly enough, Gary Bauer of all people wrote an article about Obama’s “Catholic problem” in Human Events. He does, however, hit the nail on the head: “Obama is hemorrhaging Catholic support for the same reason John Kerry lost the Catholic vote in 2004: because most Catholics believe that some issues are non-negotiable.”
Well, he almost hits it. I’m not sure “most” is correct, but he’s referring to non-lapsed Catholics.