Each side of the presidential race is now down to one nice candidate and one mean one. All political considerations aside, does it mean anything that the Democrats seem to be moving to the nice candidate and the Republicans to the mean one? With Hillary Clinton or John McCain, we'd have four years of a grating voice screeching, "Eat your peas!" and "Sit up straight!" and "Because I said so!" Barack Obama and Mitt Romney are at least pleasantly optimistic in demeanor.