This is easy. Tim Kaine is a young lightweight. You do not want to share the stage with a paler shade of Obama. You do not want people asking where's the beef. You do not want your own Dan Quayle.
Evan Bayh is an old lightweight. He looks young, but something haunts his resume like the forced part in John Edwards' hair. Evan Bayh is the John Edwards for people who have been disillusioned by John Edwards. Evan Bayh is the Bob Taft of the Democratic Party. His name is too hard to spell and pronounce, and looks like it was selected by lottery or committee at the Indianapolis Country Club Charity Invitational.
Joe Biden is a friggin' warhorse. He can crush wimps and poseurs with his two pinky fingers, and his cufflinks alone are more important than Pervez Musharraf. He is the Pat Buchanan of his generation, except without the Hitler book, or like Gary Hart without Perot Face and the crummy background. And there is nothing more post-racial, or full of hope and healing, than the eternal, prime-time redemption of this.