That lie has been circulating way too long. 19 million Catholics cast a vote for Obama but that is only 27% of the nearly 70 million voting age Catholics in this country. That means that 73% of the Catholics voted for McCain or "None-Of-The-Above".
Peace be with you
The upshot is that Obama won among eligible voters who voted, and he won by the same percentage among self-defined Catholic voters (54:47) as among all American voters at large. Give or take a percent, rounded to whole numbers, etc. etc.
Those "whole numbers" had better change this time around.
If you go in and execute a private vote, how the heck do they know how you voted and if you were Catholic, Protestant or Wiccan? Does electronic voting tell them who you are and what you believe? This is crazy.