The vast majority of the practicing Catholics I know vote Republican. (Unfortunately, I also know of some who wouldn't vote for Romney because they didn't view him as conservative enough - an opinion shared by some voters here on this forum.) IMHO, it has more to do with location: The northeast tends to vote Dem, and many Catholics live in the northeast.
Conservative Catholics can claim all they want that anyone calling themselves Catholic who votes liberal isn't REALLY a Catholic,
Catholics who vote GOP and Catholics who vote Dem are both Catholics. However, here's a factor to consider: Cradle Catholics tend to continue to self-identify as Catholic even when they no longer practice the faith. So, these exit polls may be lumping everyone together, including people who were raised Catholic but really no longer are practicing - they're secular. The real Catholic vote is reflected in those who attend Mass regularly (weekly), as we're obligated to do, and reportedly the majority of that group voted for Romney. This study is being challenged, and I don't know how accurate it is, but the numbers are at this link.
Like I said, there must be something in the water here in NY because those Catholics who are practicing Catholics who voted dem ARE cradle Catholics.
There was a comment on the RF many months ago made by a Catholic about NY Catholics. That was that there is something about the Catholic mentality that exists in WNY (Buffalo area) and he thought it was cause of the bishops who were in charge of the dioceses there. He said it was really off from what he encountered elsewhere.
Of course, that is the only Catholic I ever knew, being raised there and living there for decades.
After moving to CNY (Syracuse area) I encountered a different breed of Catholic. It’s still a heavily Catholic area, but for the most part they are quite different. A whole different mentality, although there is still my neighbor who is liberal to the core. And she tells me all her friends voted for obama because of the handouts, primarily obamacare. They want their guaranteed healthcare and medicine and SSI.