Ed Morrissey is puzzled:
If he announces at the convention, it’s going to be Hillary Clinton. A Hillary selection works best at the convention, providing a dramatic moment of unity. If he waits until the media Dead Zone, I’d guess either Joe Biden or Evan Bayh. However, one very pragmatic problem comes with Hillary: her debt. She only retired $1.3 million off of a debt that surpassed $20 million, and that would kill Obama’s fundraising advantage over McCain and that’s without counting the RNC’s whopping advantage over the DNC.