I get so riled up when I read commentary like today's extremely uncharacteristic Prudence column. The vice presidency doesn't really matter. Obama is young and healthy, and I imagine that security has never been more thorough for the president. The likelihood that a VP would actually need to take over is minimal.
So what is a VP? For Obama he/she's a symbol. User Beaujoe wrote that "[Obama] was nominated specifically as an alternative to you." Obama ran on change, to be sure (so did every other political candidate ever), but he ran on something more unique, too: uniting and coming together.
For all practical purposes, half the party voted for Clinton. I was a part of that half. By not selecting Clinton and not giving her that symbolic power, he's essentially kicking Clinton supporters while we're down. If he's not willing to put up with a name he doesn't particularly care for on his ticket, I think it reveals an enormous hypocrisy in the comprising and uniting that he's been preaching for months.