xx% McCain, 68% Obama - Don't attend church4 **
Cultural Catholics who may go to church a few times a year. This may be an undecided voter, but this vote leans to Democrats.
37% McCain, 61% Obama - Non-weekly-mass-attending Catholics6,12 > 45% McCain, 54% Obama - Catholics1,4,6,8,9,10,11,12
Sunday-morning American Catholics. This voter is a regular in the pew and may even play some leadership role in the parish. This is the true Catholic swing vote.
55% McCain, 43% Obama - Weekly mass-attending Catholics 6,9
The sweats the details Roman Catholic who goes to confession, is active in the full sacramental life of the parish and almost always backs the Vatican on doctrinal matters. This group is a small slice of the American Catholic pie.
Exit poll numbers from the 2008 Presidential Election demographics, footnoted and annotated on my profile page.
There's no separate poll number for only the "sweats the details" Catholics.
The "sweats the details" people are a small number, but they voted overwhelmingly McCain. (Anecdotally, I know maybe 30-40 of them here, and none of them were Obama supporters.)