From what I hear, the Palin selection was completely last-second stuff. Utterly unvetted. Utterly reckless. McCain was intent on Lieberman until the very last moment. If you want a commander-in-chief who will make vital decisions at the last minute, on impulse, according purely to polls and electoral tactics, against his own judgment and deferring to Rovian hacks: vote for McCain.
He's George W. Bush, without the prudence and caution.