another HUGE plus:
Bayh - Senator from Indiana. were he to be VP, the (R) governor of Indiana would appoint his senate replacement, would've lost a senate seat.
Kaine - Gov from Virginia - were he to be VP, the (R) lieutenant gov would've taken his place, giving the statehouse to an R
Biden - Senator from Delaware - he's apparently the VP candidate, meaning the (D) gov will replace him if he's elected, preserving that senate seat.
i'd like to think this went into the decision making process, if only being a piece of it. no matter what, it is a good side-result.