What the polls are telling us about November

Nate Silver looks forward -- and backward -- for some idea of what we might expect in November.  How about each candidate's "bounce" after their respective conventions?

It appears as though Mr. Obama is not on track for the large bounce in the polls that seemed possible over the weekend, when Mr. Obama’s numbers were improving at a prodigious rate in the wake of former President Bill Clinton’s speech.

Mr. Obama almost certainly had the more successful convention than Mr. Romney. But in some sense, his bounce has been fairly ordinary; conventions typically do produce bounces.

It was the very small bounce that Mr. Romney received in the polls after his convention — about two points — that is more unusual historically, and somewhat low even relative to reasonably diminished expectations. ...538

How much do past elections illuminate what we're look at now?

The more advantage an incumbent builds after his convention, the more he’ll be able to tolerate shedding a few points in the polls later.

In 2004, George W. Bush built about a five-point lead after his convention, and lost three points of that by Election Day — still enough to give him a two-point win over John Kerry. ...538

Does Mitt Romney have a chance?

Ultimately, the best reason for Mr. Romney’s backers to be pessimistic about his chances may be that the old normal wasn’t that great for him. With a two-point deficit in the polls, Mr. Romney could win the election in any number of ways, but he would nevertheless be an underdog, and especially so on the premise that voters were extremely resistant to changing their minds for any reason.

Still, Mr. Romney needs to take care of first things first, and seeing some steam come out of Mr. Obama’s numbers would be his first step on the road to recovery. ...538

In other words, Obama needs to be brought down in political ad after political ad  for Romney to pull out a tiny victory.  And we can be sure that Americans for Prosperity, Karl Rove, and friends and colleagues are working very hard to make sure that happens.