I believe I know who will be the second Catholic U.S. President.
The second U.S. President will be George W. Bush. Upon leaving office, he will follow his good friend, ex-British Prime Minister, Tony Blair, and convert to Roman Catholicism.
I base my feelings on several observations:
First, true Conservatism, is based on principles, unyielding and unchanging truths, that are valid yesterday, today and tomorrow. Believing this mindset is the fast road to the Roman Catholic Church. Beside being aligned with Conservatives on many of the social issues, the Church offers centuries of continuity in Her teachings and never bends Her eternal truths based on the trade winds of public opinion or current events. This is the reason why so many high- profile Conservatives find their way to Roman Catholicism: Larry Kudlow, Robert Bork, Sam Brownback, Laura Ingraham, Robert Novak, etc...
Second, the proper, heads-of-state protocol for addressing a Pope is for Catholics to use the greeting, "Holy Father," and for non-Catholics to use, "Your Holiness." Bush repeatedly addressed BXVI as "Holy Father" during his U.S. visit. It is a very small innuendo, but you can be sure with the etiquette staff at the White House it was not an oversight. In addition, Bush announced on his "Farewell Tour" of Europe this summer he is stopping at the Vatican to visit BXVI. He just saw him on BXVI's U.S. trip. There is no need to visit again so soon. No secular reason.
Third, during the night of the 2004 Presidential election returns, cameras where set up in the private residence of the White House. As the Bush family watched the returns, I saw a picture of the Blessed Mother on the Bush's end table. A picture of the Blessed Mother on a Protestant's end table? What gives?
Fourth, GW Bush's brother Jeb Bush, the popular ex-Governor of Florida, converted to Catholicism. He has set a precedent (no pun intended) and the trail is blazed already in the family.
A Washington Post article in April of this year cited many clues as well including: GW Bush telling his cabinet that he was reading BXVI's book; Fr. Richard Neuhaus tutoring the President on Catholic doctrines; Karl Rove incredibly getting a priest to bless the White House; the President freely using terms coined by the papacy (culture of life/dictatorship of relativism) and Bush having a personal respect for the concept of the primacy of the Papacy.
Former Pennsylvania Senator Rick Santorum was the first to joke that Bush was a Catholic president. Many a truth is said in jest, Senator.