Right when it looked like there was a moment of clarity, Pew comes out with a new poll showing Romney ahead by 4 points among likely voters. The new data has conservatives celebrating and liberals in a panic, but here are three important pieces of context:
1) Throughout the entire cycle, Pew has had a strong Obama-lean, making the result particularly surprising. And Pew Research has irreproachable credentials, both in terms of past results and methodology, so this is a very important and powerful data point in the direction of a Romney bounce.
2) The Pew poll swung 12 points in Romney's direction, from Obama plus-8 to Romney plus-4—that kind of a swing is not especially plausible. In fact, every other poll has shown a swing of 6 points or less since the first debate. That doesn't mean, though, that the new poll is necessarily out-of-whack. The first poll, and not the second, may have been the inaccurate one. But while it's not especially productive to dig into the weights to guess which poll is most representative (party-ID! party-ID!), it is important to recall that there can be outliers: remember the vaunted Ann Seltzer showing Obama leading by 13 in June? And although Pew's last poll was certainly good for Obama, it was not necessarily an outlier.
3) Analysts and horserace watchers face a choice between trying to reconcile Pew with the available data or waiting for more information. In my view, the Pew poll is largely irreconcilable with the other information, which now shows everything from no change to a 12 point shift in Romney's direction. The answer is probably somewhere in the middle, but whether it's 3 or 6 makes a huge difference. Given the extent to which the data conflicts, the right choice is probably to wait a few days before drawing conclusions. By later this week, the Pew poll will probably appear as an outlier—or, it might be the first sign of a new race, with Romney in the lead. Either way, it's more evidence that Romney is making gains.