Here you go. 2012:
Protestant (29% of voters) Romney won 62-37
Catholic (25% of voters) Obama won 50-48
I though total Protestants made up more than 50% of the electorate.
Link:
http://www.pewforum.org/2012/11/07/how-the-faithful-voted-2012-preliminary-exit-poll-analysis/
Where did the 29% figure come from? Was it just evangelicals?