@ehBeth,
Agreed, and the Clinton supporters who won't support Obama don't fall into that category (because of her politics). But I think some of them might see it as gimmicky to add a woman to the ticket this late who didn't get there on her own.
But all that being said I really think the constituencies weren't as big as simply being a woman and undercutting part of Obama's "change" appeal.
Now there is going to be change on that kind of level (first this, first that) no matter what.