Check out Andrew Sullivan's piece for the Times online. Highlights:

There is one reason the job of vice-president exists. In a system with a single executive, you need someone to fill in if the president is incapacitated or dies. ...The pick is also the first presidential-level decision a candidate has to make. You learn a lot about the candidate...

In Joe Biden, Obama revealed his core temperamental conservatism. It was a safe choice of someone deeply versed in foreign policy, and with roots that connected to the working class white ethnics he needed. It wasn't flashy; and was even a little underwhelming; but it was highly professional.

What we have learned about John McCain from his selection of Sarah Palin is that he is as impulsive and reckless a decision-maker as George W. Bush. We know this not because of what we have learned about this Pentecostalist populist since she exploded on the scene last Friday morning (and God knows we have learned more than we ever wanted). We know it because of how McCain made the decision. He wanted his best friend, Joe Lieberman, the former Democratic vice-presidential candidate for Al Gore. That pick would have been remarkable for its bipartisan nature, would have impressed independents, and signaled a centrist presidency centered on foreign policy. It would have been bold while not being rash.

But McCain is in charge of a party that is now, at its core, religiously motivated. Joe Lieberman, for all his political talents, is Jewish, pro-choice on abortion, gay-inclusive, and domestically liberal. McCain faced an insurrection in his party base if he picked him. Without the evangelical base, he wasn't going to win.

So last week, McCain picked someone he had only met once before. I repeat: he picked someone he had only met once before. His vetting chief sat Palin down for a face-to-face interview the Wednesday before last. It's very hard to overstate how nutty and irresponsible this is. Would any corporate chieftain pick a number two on those grounds and not be dismissed by his board for recklessness?