Will Paul Ryan Run for President?

That is the question asked by Jonathan Chait over at the New Republic, and Chait thinks Ryan must be contemplating it, or is at least positioning himself to jump into the race if the field does not get stronger. Chait's backstory on Ryan and the Weekly Standard is especially interesting.
One thing Chait does not mention is this: Ryan is a Catholic and social conservatives view conservative Catholics as kindred spirits, and have ever since the Rev. Jerry Falwell used to boast that a third of the membership of his Moral Majority consisted of Catholics.