In three state polls — Pennsylvania, Wisconsin, and Florida — Romney shows signs of gaining on Obama. Here's our guide to today's polls and why they matter.

Findings: Obama's lead is down in Pennsylvania from a June poll. He currently leads Romney 44 percent to 38 percent with 15 percent undecided. In June he led 48 percent to 36 percent. 
Pollster: Franklin & Marshall College
Methodology: Interviews of 681 Pennsylvania-registered voters between August 7 and August 12 with a margin of error of +/-3.8 percentage points.
Why it matters: Paul Steinhauser of CNN points out that Pennsylvania hasn't been won by a Republican in a presidential election since 1988, but Romney is getting closer to changing that despite Obama's slim lead. Writing for the Philadelphia Daily News, Will Bunch puts the poll in the context of a judge's upholding of the state's voter identification law, which Democrats say will hurt them. Bunch says the poll "raises as many questions for November as it answers."
Caveat: The numbers above don't take into account voters who lean one way or another. In that case Obama leads 47 percent to 42 percent, with only 7 percent remaining undecided.

Findings: Romney is up in Wisconsin 48 percent to Obama's 47 percent. A reversal from a 49 to 46 percent Obama lead in July.
Pollster: Rasmussen
Methodology: Automated poll of 500 likely voters in Wisconsin August 15 with a margin of sampling error of +/-4.5 percentage points with "95% level of confidence."
Why it matters: This is Wisconsin, Paul Ryan's home turf, and 57 percent of voters view the  veep-pick favorably. The Hill points out: "This is not the first time in this election cycle the right-leaning pollster has found a swing in support in Wisconsin after a significant political event" since Romney also overtook Obama after Governor Scott Walker won the state's recall election. 
Caveat: Rasmussen's conservative. 

Findings:  Romney leads Florida 45 percent to Obama's 43 percent, expanding his lead from last month by only a point. 
Pollster: Rasmussen
Methodology: Automated poll of 500 likely Florida voters August 15 with a margin of sampling error of +/-4.5 percentage points with "95% level of confidence."
Why it matters: This is the second poll in two days to show Romney with a slim lead in Florida, however, in the Purple Insights poll, Obama was gaining on him, making it a one-point race. Here Romney's lead has widened by a point. 
Caveat: See above. Also, according to the poll 48 percent say they fear Obama's health care law more than Ryan's Medicare proposal, while 41 percent say the opposite.