[roni]

I think Bill Richardson makes some sense for the Democrats. African-American and Latino's combined make up 1/4 of the US population. Going for high turnouts and high vote-getting totals from these demographic groups could offset losses among demographic groups that Obama has not done well with during the primary season.

Alternately, he could pick someone who got the votes of those groups with which he didn't fare so well during the primary season.

Those would be my top two choices - but I am sure there are others not popping to mind right now.