Constitutional FAQ Answer #135
Q135. "It was my understanding that the Constitution forbade its president to be a Roman Catholic, but after many years this was deleted because it was later deemed to be 'politically incorrect'. Is this true?"
A. There has never been anything in the Constitution, in any draft or version, that stated anything of the sort. You need only read the original to see for yourself — photographic copies are available at this site and at the National Archives site. A quick scan of the debates of the Convention, as transcribed by Madison, reveals no mention of the word "Catholic" as well. I fear you've hit upon another Internet myth.