Undecideds will break for...?

[TJ in Oregon]

The undecideds normally break against the incumbent. They've had 4 years to know Obama. If they haven't convinced themselves to vote for him by now they likely won't.

There almost as many times where the undecideds break FOR the incumbent than against them.

IIRC his analysis showed that to be true early on in the campaign, particularly over the summer, but by mid-October the remaining undecideds tended to break toward the challenger.