I don’t usually write about partisan politics (I find the whole thing rather depressing), but reading the news coverage today about Rudy Giuliani and John Edwards dropping out of the presidential race, I had the following thought. Suppose that the Republicans ultimately nominate John McCain and the Democrats nominate Hilary Clinton. Who should be McCain’s vice-presidential running mate? I have a suggestion, assuming that winning the election is the sole criterion in making the choice: McCain should choose Barack Obama.