Although the topline results don’t make it obvious, it appears that John McCain had a fairly strong night of polling in the daily tracking polls, which are the only numbers we have to look at today.
Wednesday: Obama +7.8
Thursday: Obama +2.4
Friday: McCain +4.2
So Obama’s numbers are being propped up by a strong night of polling on Wednesday, which will cycle out tomorrow. He also held up relatively well on Thursday following Sarah Palin’s speech (note: our estimate of his Thursday numbers has been revised slightly upward from yesterday’s figures because of a methodological improvement I made to my tracking poll algorithm). But yesterday, McCain had a good night, most likely leading by somewhere in the range of 4 points. There is a good chance that tomorrow’s Gallup numbers will show a tie or a McCain lead.
As for Rasmussen , it actually has Barack Obama gaining a point, and moving into a 3-point lead. However, it still looks like McCain may have had a relatively good night on Friday. My tracking poll algorithm will have more difficulty with the Rasmussen tracker than the Gallup tracker because Rasmussen uses a more complicated weighting procedure (i.e. weighting by party ID), meaning that we’re a step further away from seeing “raw” numbers. But with grain of salt, here is what I show:
Wednesday: Obama +4.9
Thursday: Obama +3.8
Friday: Obama +0.3
Once again, I would caution against overinterpreting any of this. Conventions should produce bounces — they are the equivalent of tens of millions of dollars in free advertising time. What we don’t know is how to contextualize these bounces. An average convention bounce is about 6 points, but we don’t know how the Democratic and Republican conventions interact with one another, particularly as it affects the timing of the respective bounces. Moreover, Fridays (and Saturdays) are tough nights to poll. My hunch, as I’ve stated before, is that whatever numbers McCain winds up with over the weekend, Barack Obama will probably be polling a couple of points ahead of those numbers by the end of the upcoming week.