It's remarkable Tim Kaine is even being considered. Check out this catch from Jonathan Tasini:
Just this week the Virgina House rejected his nominee to be Secretary of the Commonwealth (Virginia's past head of the AFL-CIO Danny LeBlanc) and here's what Kaine said:
"I am saddened that the House leadership has chosen the Washington style path of partisanship by rejecting a good and capable man...The Secretary of the Commonwealth has no - I repeat, no - role in the enforcement of Virginia's right-to-work law, a law I strongly support."
I added the emphasis. I could see a guy making a statement--though I still think it would be a sad comment--that he would enforce the laws of Virginia, which includes right-to-work. But to say publicly he STRONGLY SUPPORTS anti-union laws is unacceptable.
via Kathy G is my source for anti-Kaine discussion, but I wanted to point this out because it really is egregious. I know that Democrats in conservative areas have to speak in certain ways to communicate and work with their constituencies and the various elites in their areas, and that this leads to some inevitable friction. But there are certain principles you don't compromise or else getting Democrats in office becomes irrelevant. Supporting Right to Work laws which make it impossible to organize a union is one of them. It's just not ok for workers to have no opportunity to stand up for themselves against abusive labor practices; someone like Kaine shouldn't just be off the table, he should be toxic.
And as KathyG notes, Kathleen Sebelius is in a more conservative state than Kaine, and she has a pretty progressive record on these same issues.