He tried to toe a fine line and screwed up. He's got to keep finance happy in order to run for higher office, but if he pisses off the Democratic base by being too friendly to Wall Street he'll lose anyway.
I've often quoted whoever said "Politicians have to LOOK good to voters, and DO good for donors".
But that quote has rarely been more fitting than the current situation of money corrupting politics where Democrats need to balance Wall Street money and Wall Street reform.
That's what gets us an Obama, talking progressive and doing Republican a lot.