Sen. Joe Biden has a history of running his mouth a little too long and getting himself into hot water, so Barack Obama’s in for some tense moments when his newly appointed attack dog starts barking. Of course, though I’ve exploited one of his verbal gaffes, Biden’s no dummy. He’s been a senator four nearly three decades, for Pete’s sake. Still, with all that experience comes the propensity to ramble. How hard will it be for Biden to stay focused on Obama’s message?