Obama Camp Hostile to Liz Warren?

What does lefty Steve Rattner, the former Obama car-czar, have against Elizabeth Warren? He doesn't explain, but Joe Scarborough jokes that he's ready to support Scott Brown.

Mika: I think she's going to be great...

Rattner: She'll be great at Harvard Law School when she's back there after the election.

Some explain Rattner's hostility by pointing out that he's a Wall Street guy and doesn't like how tough Warren is on the industry, but that seems a little too pat for Warren, doesn't it?