Two national polls show Obama with leads of nine and seven points. A poll in Iowa shows Romney up by a slim margin. Here's our guide to today's polls and why they matter. 

Findings: Obama leads Romney by nine points in a new Fox News poll with 49 percent to Romney's 40 percent. That's up from July when he led by only four points. In a CNN/ORC International poll he leads by seven percentage points — having 52 percent to Romney's 45 percent — among registered voters. In their most recent previous poll Obama led 49 percent to 46 percent. Talking Points Memo notes that in this poll Obama had a 53 percent to 42 percent lead among independent voters, a big change from the July poll when Romney led them 49 percent to 42 percent.  

Pollster: Fox NewsCNN/ORC International 

Methodology: For Fox News: 930 registered voters were polled between August 5 and 7 via telephone using live interviewers. (The poll had an oversample of "115 randomly selected Hispanics.") The margin of sampling error is +/-3 percentage points. For CNN: 1,010 adults — including 911 registered voters — were interviewed via telephone August 7 through 8. The margin of sampling error for the total is +/-3 percentage points. 

Why it matters: These two follow other polls that have come out as of late showing Obama with a substantial lead, and they are prompting a Romney adviser to push back, according to Politico. The senior adviser, who spoke on background, argued that there has been no national news to precipitate the change. “Guys, it’s the middle of summer, it’s the dolldrums, it's the middle of the Olympics," he said. However, National Journal's Matt Vasilogambros points out that the numbers do come "after a series of overseas gaffes and a barrage of attack ads." The adviser pointed to Gallup and Rasmussen tracking polls, which he said show that the big-Obama-lead polls were wrong. Yesterday we pointed out that Rasmussen's tracking poll had Romney up by four points. That stands today. As for Gallup they are tied

Caveat:  We've pointed out before that averages coming from places like Real Clear Politics, The Huffington Post, and Talking Points Memo show Obama with a lead, but not that big of a lead. That said, Talking Points Memo's Poll Tracker shows Obama up 5.9 over Romney, pretty close to the CNN number.  Alexander Burns Politico wrote of the Fox News poll: "few people involved in the 2012 race think Obama has this kind of advantage over Romney."


Findings: Some good news for Romney: he's up by two in Iowa, 46 percent to Obama's 44 percent. 

Pollster: Rasmussen

Methodology: 500 likely voters in Iowa were surveyed August 8 by automated poll. The margin of sampling error is +/-4.5 percentage points "with a 95% level of confidence." 

Why it matters: Iowa's definitely still in the air. Romney stopped by there this week and Obama's heading there next. 

Caveat: Rasmussen leans Republican.