Republican nominee Mitt Romney leads President Barack Obama by 2 points, according to a new national survey from Democratic-leaning Public Policy Polling (PPP). The poll, conducted on behalf of Daily Kos and Service Employees International Union (SEIU) in the days following last Wednesday's debate, shows Romney edging Obama among likely voters nationwide, 49 percent to 47 percent. Obama held a 4-point lead in last week's PPP survey. Romney also took a big chunk out of the president's 15-point lead among women from a week ago. PPP now shows Obama leading by only 6 points among female voters.

Seriously: has that kind of swing ever happened this late in a campaign? Has any candidate lost 18 points among women voters in one night ever? And we are told that when Obama left the stage that night, he was feeling good. That's terrifying. On every single issue, Obama has instantly plummeted into near-oblivion. He still has some personal advantages over Romney - even though they are all much diminished. Obama still has an edge on Medicare, scores much higher on relating to ordinary people, is ahead on foreign policy, and on being moderate, consistent and honest (only 14 percent of swing voters believe Romney is honest). But on the core issues of the economy and the deficit, Romney is now kicking the president's ass

Polls have very low response rates. Sometimes short-term events that dominate the news cycle excite partisans and make them more likely to answer pollsters -- it happened when Romney picked Paul Ryan -- but they don't reflect a deep remaking of the public opinion landscape, which remains fairly settled. 

On the other hand, a continued series of events like last week's debate really might change the narrative of the race. And here is the bad news for Democrats: Their best shot has already come and gone. The debates will anchor the campaign narrative from here on out, and the three debates that follow all offer less favorable terrain for them to press their case.