The uproar over South Carolina Governor Mark Sanford's affair raises the issue of marital infidelity again. But given the high profile of the case, and that the mistress in question was a longtime friend, many people have an opinion.Especially about whether Mrs. Sanford, Jenny, as she's known, should stay or leave?But what if it was Barack?What if Obama cheated on Michelle? Would Michelle be any less of a woman for staying there? Would she be able to maintain her "dignity and respect," if she left?