Today's Gallup numbers? In their likely voter screen, Mitt Romney leads by a whopping 7 points, 52-45. On the other hand, they have registered voters at 48-47, with Romney barely leading. Meanwhile, Barack Obama's approval rating (measuring over three days, rather than the seven they use for head-to-head) ticks back up to 50%. Huh?
It is highly likely that something is going wrong here -- a six point gap between registered and likely voters is just too high given how many registered voters actually vote, and a 50% approval rating (and the previous three days was at 48%) really isn't consistent with getting crushed by seven points.
So what should we want to do with that number if we want to know who will win? Regular readers know my answer: what we should do with every polling number. Ignore it, and look at the polling averages and the good poll-based predictions. Really; if we were smart, we would all ignore all the individual state and national polls and just keep an eye on, say, the Pollster national average and Nate Silver's current prediction.
Everything else is just going to be running up against the limits of what the polls can really tell us.
In particular, it's a waste of time to try to piece together what's going on with Gallup. Perhaps it's some sort of screwy random effect. Perhaps they're exactly correct, and everyone else is wrong. Perhaps they just have a lousy likely voter screen.
It doesn't really matter. Toss it into the soup, and that's the end of it. And, yes, I definitely do think that those who are doing the polls-of-polls should certainly be including Gallup, even though it's very likely something weird is going on. Of course.
Now, do I take this advice? Well...not exactly. I click over to Gallup every day when the numbers change. But I do feel quite foolish every time I do it. And I am most definitely avoiding as best I can complaints from both sides about polls being slanted against them. Toss it in the pot, and that's the end of it.