Obama still on defense against Romney after second debate—right where he wants to be

Woody Allen is often quoted as saying that "80 percent of success is showing up." Hackneyed though this expression has become, it applies quite accurately to the election as it stands today. President Barack Obama showed up at the debate on Tuesday night and stabled his teetering campaign.

Given the wide consensus that Obama did not mentally show up for the first confrontation with former Gov. Mitt Romney, his combativeness and general vigor appeared to convince the television audience that he still has some fight left in him. Instant polls suggest that Obama scored well overall and, more critically, with undecided and leaning voters. Polls of overall voters are not that meaningful, because most people will say their candidate won. But surveys of undecided and leaning voters, like those from CBS and Xbox/YouGov, give us valuable clues. Obama clearly outperformed Romney in both.

The Signal's real-time forecast, heavily influenced by prediction markets at this point in the campaign, ticked up nearly 3 percentage points during last night's debate.

Sources: Betfair, Intrade, IEM, HuffPost's Pollster, RealClearPolitics

The national polls have been trending toward Romney since the first presidential debate on Oct. 3, beginning immediately afterward and setting the trajectory of the campaign through the vice presidential debate. Tuesday evening's face-off will have shorter legs, with the next debate set for Monday, Oct. 22, but between the instant polls and markets we suspect it will halt Romney's advance. The president's best offense remains a good defense: If he can hold off Romney in Ohio, and generally hold his ground for three more weeks, the election is his.

Follow the state-by-state and overall presidential predictions in real time with PredictWise.com.

David Rothschild has a Ph.D. in applied economics from the Wharton School of Business at the University of Pennsylvania. Follow him on Twitter @DavMicRot