Last week, while everyone was saying that the Democrats were not getting a bounce from their convention, I was one of the first people to note that there were hints of a big 8-10% bounce toward Obama, based on changes in the last day of one 3-day tracking poll.
Now I'm seeing the same thing for the same reasons in the Republican direction (though because of a CBS poll conducted before Palin's speech but released yesterday showing a dead heat, I am far from the first to note a probable Republican bounce).
Today, both the Gallup and the Rasmussen tracking polls are showing a 3% move in McCain's direction from the day before. That means that respondents polled on Thursday were 8-10% more favorable for the Republicans than those polled on Monday. If polling on Friday and Saturday continues in the same direction, that would point to a dead heat or insignificant lead for McCain by the 3-day tracking polls released on Sunday.
As I noted before, this might well not happen. There is a reason that the polling agencies use three-day averages.