Here's my prediction: Whoever Obama picks for VP will be ruled the "most liberal" in whatever office the person holds, unless it is a senator, in which they will be the "second most liberal".
Here is the starting point:
http://nj.nationaljournal.com/...
So, if Obama chooses a governor:
"The most liberal senator chooses the most liberal governor as a running mate"
If he chooses a Rep:
"The most liberal senator chooses the most liberal Congress(wo)man as a running mate"
If he chooses a Senator:
"The first and second most liberal senators are running together"
(They made a similar claim in 2004 with Kerry/Edwards:
http://www.govexec.com/... )
I feel pretty confident in this prediction. It's almost like predicting the sun will rise in the East tomorrow morning.