President Obama and Mitt Romney will meet for their third and final presidential debate tonight at 9 pm ET. It will be streamed live on YouTube.
Harry Enten: "Historically, the third debate has had little impact. The average change in margin since 1988 just before the third debate and after is only about a point, compared with 2 points for the first debate. This small effect likely has to do with the fact that the third debate takes place very late in the campaign, and there is little the candidates can do now that would be all that surprising."