Over at the Atlantic, Marc Ambinder is reporting that the addition of Sarah Palin to the Republican ticket "has produced an outpouring of volunteers for the GOP's get-out-the-vote program ... countywide, seven to ten times as many new volunteers are signing [up] to help as compared to the same days a month ago."
Clearly, Palin's helping John McCain's campaign quite a bit right now. But one potentially significant effect of her presence may not be felt until just a few days before Election Day, when the GOP's vaunted get-out-the-vote efforts really begin.
McCain had a real weakness because of the lack of enthusiasm for him in the evangelical community, which has traditionally provided the foot soldiers for Republican GOTV work. They probably would have still voted for him, but if he had picked someone else, they might not have shown up to work for him. For now, it seems, that problem has been solved.