Pew shows Mitt Romney leading by four points, the tracking polls paint a confusing picture, swing state polls show President Obama leading by a small margin, and fewer Obama supporters than Romney supporters are "extremely likely" to vote. Here's our guide to today's polls and why they matter. 

Findings: Romney leads Obama nationally among likely voters by four points among likely voters, with 49 percent to Obama's 45 percent.
Pollster: Pew 
Methodology: Telephone interviews of 1,112 likely voters October 4 through 7 with a margin of error of +/-3.4 percentage points. 
Why it matters: This is a big reversal from a Pew poll last month which showed Obama up by eight, and is an indication that Romney's debate win has some effect on the overall state of this race. 
Caveat:  Talking Points Memo's Tom Kludt writes other pollsters have shown a less dramatic post-debate shift.


Findings: Obama is up 50 percent to Romney's 45 percent in Monday's Gallup tracking poll, but in a separate post Gallup notes that, since the debate, the race has moved into a tie. Rasmussen's tracking poll has the race tied with each candidate at 48 percent each.
Pollster: Gallup, Rasmussen  
Methodology: For Gallup: Seven day rolling average of telephone interviews with 3,050 registered voters with a margin of error of +/-2 percentage points. For Rasmussen: Telephone survey of 500 likely voters a night in a three day rolling average with a margin of error of +/-3 percentage points. 
Why it matters: So these numbers are kind of baffling. Business Insider's Joseph Weisenthal tweeted: "Wait, seriously. Gallup Obama +5? Joke, right?" Now, Gallup's seven-day average — October 1 through 7 — gives Obama the five point lead whereas its numbers from October 4 through 6, after the debate, show the race tied. The Huffington Post's Mark Blumenthal said the debate has showed a "dramatic tightening" in tracking polls. That said, The New Republic's Nate Cohn tweeted, "Between Rasmussen, Gallup, and PPP's tweets about their nightly samples, there's a strong case that Romney's bounce was short-lived." Cohn previously explained that "some of the worst news for Mitt" is coming from Rasmussen which "initially lurched in Romney's direction" and now shows a tied race. 
Caveat: It's kind of clear at this point that nothing's really clear. 


Findings: Obama is up by 2 points in Iowa and 1 point in Colorado according to Rasmussen. Obama's up by 3 in Virginia, according to Public Policy Polling.
Pollster: Rasmussen, Rasmussen, Public Policy Polling 
Methodology: For Rasmussen Iowa: Automated poll of 500 likely Iowa voters October 7 with a margin of error of +/-4.5 percentage points. For Rasmussen Colorado: Automated poll of 500 likely Colorado voters October 7 with a margin of error of +/-4.5 percentage points. For PPP: Automated poll of 725 likely Virginia voters October 4 through 7 with a margin of error of +/-3.7 percent. 
Why it matters: Now these aren't huge leads for the president, but also aren't putting him behind Romney as some did at the end of last week. "Rasmussen's decent results for the president were consistent with a strong polling day in the national tracker, as well as in PPP's poll of Virginia," Cohn says. Though he notes that in general polls have shown that Romney "has made gains since the debate," he adds: "Rasmussen has conducted more post-debate polling than any other source, so it's worth noting that their data is driving the numbers back in Obama's direction." 
Caveat: Rasmussen typically leans Republican and PPP leans Democratic.


Findings: While 86 percent of those who support Romney say they are "extremely likely" to vote, only 73 percent who support Obama do. Similarly, 84 percent of Republicans say they are "extremely likely" to vote while only 76 percent of Democrats do. 
Pollster: The Tarrance Group and Lake Research Partners for Politico/GWU 
Methodology: Survey of 1,000 registered likely voters October 1 through 4 with a margin of error of +/-3.1 percentage points. 
Why it matters: If Obama's supporters don't get out and vote that's bad news for the president. In fact, the poll shows that Romney leads Obama 52 percent to 46 percent among those deemed "extremely likely" to vote, where the race is nearly even among just likely voters with Obama a point ahead. Politico's James Hohmann explains: "The electorate is deeply divided and polarized, which makes 2012 look increasingly like a base election. Whoever runs up their vote count among their core supporters is likely to prevail, which is why these numbers are so significant." 
Caveat: "Most of the poll’s calls were made before Romney’s strong performance at the first presidential debate in Denver," Hohmann says.