BRTD, have you ever heard of "cafeteria Catholics"? I'd wager they're a lot more common and real than whatever poorly-supported anecdote Superwhoever brought up once over four years ago.
You really do have a perplexing and hard-to-defend blind spot when it comes to these matters.
Actually, his point was that such people would be reluctant to vote for a ticket with an ex-Catholic on it. Basically he argued that to a lot of Catholics, including many swing voters who obviously did not agree with the church on everything, a ticket with a pro-choice Catholic would be seen as more tolerable than one with a pro-life ex-Catholic, basically rejecting the church trumps rejecting some of the church's teachings. I don't necessarily agree with this, but being pro-life does give some cover, imagine the howls that would come from groups like the Catholic League if a pro-choice ex-Catholic ever was on the Democratic ticket.
But of course I'm aware of such people. I just don't get why anyone would continue to affiliate with such an organization. You don't hear about cafeteria Southern Baptists do you? That's because people who are more liberal than that group leave it. Also consider that basically no one in my subculture identifies as Catholic, no I don't go around shows polling people about their religion or anything, but I've been pretty active on lots of forums where heated religious debates come up and am quite aware of the Christian hardcore scene, there are probably more atheists at your average Christian hardcore show than Catholics. Hell this song is from a Christian hardcore band.
Part of the reason you don't see as many leave is because the group that disagrees with the leadership is so large. Its not like the Southern Baptists in which someone who disagrees with the leadership has only a small amount of others that disagree with their leadership. Also to many its more of an idenity than a religious belief system.