There are over 34 million registered Catholic voters in this country. President Obama got 12 million Catholic votes, or 54% of the votes cast by Catholics. The story no one talks about is the fact that Obama only got a little more than 1/3 of the actual Catholic vote with the an equal number of Catholics voting for "none of the above". I have no reason to believe it is any different in congressional elections.
Catholic Conservatives can assume that it was a good thing that the registered Catholic voters that did not vote, did not vote, a reasonable guess is that they would have gone more than 54% for Obama, let the non-voters and non-absentee voters, stay home. The Democrats know what they are doing when they try to drag them to the voting booths.