WASHINGTON -- Incumbent Republican Rep. Erik Paulsen leads his Democratic challenger Terri Bonoff in a Republican poll out Monday, but 12 percent of respondents said they were still undecided.

Paulsen leads Bonoff 57 percent to 31 percent in a poll paid for by the American Action Network, a c(4) run by former GOP Sen. Norm Coleman. The poll, whose margin of error is 4.9 percent, captured 402 registered voters in telephone interviews gathered Aug. 9-11. It was conducted by the polling firm Newton Heath LLC. 

The Third Congressional District spans the Twin Cities' western suburbs and is considered a swing district. Paulsen has successfully won three terms, yet President Obama won both in 2008 and 2012.

Bonoff is a state senator from Minnetonka. Her camp said Monday that once voters "learn of Paulsen's anti-choice, anti-LGBTQ, anti-environment and pro-gun record, the race is tied."