What would the upsides and downsides be of Tim Kaine as VP choice in 2016?

[Mister Mets]

Upsides
- Has executive experience as a former big-state Governor.
- Has campaign experience as a former DNC chairperson.
- As a former Lieutenant Governor and DNC chair, he can make sure he won't overshadow the presidential nominee.
- Is involved in national issues as a Senator. Unlikely to make serious gaffes.
- Used to media scrutiny as national party spokesman, and candidate in high profile election in major media market.
- Comes from a very important swing state (Virginia was closest to the national vote in 2008 and 2012.) Keeps winning elections there.
- Fluent in Spanish.
- Under sixty. Not too old for Hillary Clinton. Not too young for Kirsten Gilibrand.
-  His diverse experience means he's ready to be President on day one, but that there isn't any one item on his resume to make a Democratic nominee seem puny in comparison.
- Decent Democratic bench in the state ready for a sudden Senate vacancy.
- Handled himself well in a campaign against a man once seen as a potential President. This suggests he'd do well in a VP debate.

Downsides
- Has held political office since 1994.
- Virginia's essentially part of the Acela corridor now.
- Not exciting.
- A man with greater political gifts has a similar background, and helps more in Virginia.

He was the first Governor to back Obama in the 2008 primary, so he might have earned the enmity of the Clintons. It's likely to be a non-issue. If Obama is unpopular, his other offices suggest he won't be dragged down by association, any more than any other Democrat.

[Mister Mets]

I think Kaine would be a better pick than McAuliffe, but there are a few arguments for McAuliffe.

He ran a disciplined campaign and won in a swing state over the attorney general in an off-year election that tends to go badly for the party in the White House.

He is a Clinton loyalist, but that comes with a few advantages. It's easy to spin it as Hillary Clinton choosing someone she knows that she can trust, which can be an unfavorable comparison if the Republican nominee picks someone he doesn't know very well (IE- Papa Bush and Dan Quayle, John McCain and Sarah Palin.)

There is an argument that McAuliffe had a background that fits Virginia, but not any other state, although I don't think things usually work that way in purple states.