The race to succeed retiring Rep. David Obey (D-Wis.) appears to be one of the most competitive in the country.

Democrat Julie Lassa's campaign released an internal poll Tuesday that shows her trailing Republican Sean Duffy by a single point.

Lassa was at 41 percent support, Duffy was at 42 percent and there were 10 percent undecided in the poll by the Washington-based Garin-Hart-Yang Research Group. The remaining 7 percent went to independent conservative candidate Gary Kauther. The survey of 504 likely 2010 voters in Wisconsin's 7th district was conducted Sept. 26-27. It had a margin of error of plus or minus 4.4 percentage points.

Democrats have made it clear they'll fight to hold this district while Republicans sense a pick-up opportunity. The Democratic Congressional Campaign Committee's first IE ad targeted Duffy, and the National Republican Congressional Committee's IE has also aired an ad in the district.