Still, the disagreement between polls this week was on the high end, and that makes it harder to know exactly what the baseline is heading into Monday’s debate. The polls-only model suggests that Clinton is now ahead by 2 to 3 percentage points, up slightly from a 1 or 2 point lead last week. But I wouldn’t spend a lot of time arguing with people who claim her lead is slightly larger or smaller than that. It may also be that both Clinton and Trump are gaining ground thanks to undecided and third-party voters, a trend which could accelerate after the debate because Gary Johnson and Jill Stein won’t appear on stage.
In football terms, we’re probably still in the equivalent of a one-score game. If the next break goes in Trump’s direction, he could tie or pull ahead of Clinton. A reasonable benchmark for how much the debates might move the polls is 3 or 4 percentage points. If that shift works in Clinton’s favor, she could re-establish a lead of 6 or 7 percentage points, close to her early-summer and post-convention peaks. If the debates cut in Trump’s direction instead, he could easily emerge with the lead. I’m not sure where that ought to put Democrats on the spectrum between mild unease and full-blown panic. The point is really just that the degree of uncertainty remains high.