President Obama won the debate, tracking polls are up and down, and Sen. Ben Nelson's lead is shrinking in Florida. Here's our guide to today's polls and why they matter. 

Findings: Insta-polls give the final round to Obama. In the CBS poll of uncommitted voters, he won by a 30-point margin. The victory wasn't quite so large in a Public Policy Polling poll of swing states, which found Obama was up by 11 points. In CNN's poll Obama only won by 8 points.
Pollsters: CBS News, Public Policy Polling, CNN/ORC International 
Methodology: For CBS News: Online poll using GfK's web-enabled KnowledgePanel of 521 uncommitted voters. For PPP: Automated poll of 500 swing state debate watchers. For CNN: Survey of 448 registered voters. 
Why it matters: Obama had a good night. As Nate Silver points out, averaging the CNN and CBS poll with a Google Consumer Surveys poll putting him up by about 10 points gives the Obama team a 16-point margin, the biggest victory his ticket has had in the debates. (Romney, however, averaged a 29-point win after the first debate.) "Still, with the contest being so tight, any potential gain for Mr. Obama could matter," Silver writes.
Caveat: Silver also points out that foreign policy, the topic of this debate, tends to not matter as much to voters as much as economic policy. Though, they talked about that too.


Findings: The tracking polls show quite different results. Here's they are in order from widest lead for Romney to widest lead for Obama:

  • Gallup sees Romney ahead 51 percent to 46 percent, a 1-point change in Obama's favor since yesterday.
  • Rasmussen finds Romney ahead 50 percent to 46 percent, up from a 2-point Romney lead Sunday.
  • Reuters/Ipsos finds Obama ahead 47 percent to 46 percent, after showing a tie.
  • IBD/TIPP finds Obama ahead 46.5 percent to 44.5 percent, down from an almost 6-point lead Sunday.

Pollsters: Gallup, Rasmussen, IBD/TIPP, Reuters/Ipsos
Methodology: Daily tracking for all. 
Why it matters: Is this Gallup finally letting up on Romney's lead a little? It's only a point, but it's movement. Two polls out yesterday evening gave Obama 1- and 2-point leads. That said, Rasmussen points out that in their poll: "Other than brief convention bounces, this is the first time either candidate has led by more than 3 points in months."  Plus, Nate Cohn at The New Republic points out, "Obama’s support among white voters has fallen beneath the range consistent with reelection, even if minorities vote at the same rate that they did four years ago." 
Caveat: Even though Obama only has a 1-point lead in the Reuters/Ipsos poll, Reuters' Andy Sullivan points out the poll projects a comfortable victory for Obama in the electoral college: 332 votes to 206 votes. And if this debate contributes to something of a bounce for Obama, we'll have to wait a little longer to see it in the tracking polls. 


Findings: In the Florida Senate race, Democratic incumbent Bill Nelson leads challenger Connie Mack by 4 points a new poll.
Pollster: PPP for Scripps Treasure Coast Newspapers/WPTV NewsChannel 5 
Methodology: Poll of 800 likely voters October 17 through 18. 
Why it matters: Nelson's lead is slimming in what could mean renewed hope for Senate Republicans. A PPP poll taken October 12 through 14 showed Nelson with an eight-point lead. Melissa Holsman at TCPalm.com turns to Casey Klofstad, a University of Miami political science professor, who explains that the "statistical dead heat" is troubling for incumbent Nelson. In the Real Clear Politics average he's doing a little better, leading by 5.5 points.
Caveat: According to Peter Bergerson, a political science professor cited by Holsman, the presidential race has "has sucked all of the political oxygen out" of the state, and not as many have been focused on the senate race.