State Sen. Julie Lassa (D) released a poll Tuesday showing her statistically tied with former local District Attorney Sean Duffy (R) in the heated race to replace retiring Rep. David Obey (D). A poll taken for the Duffy campaign in the same week, however, showed him ahead.

The Garin-Hart-Yang Research Group survey taken for Lassa’s campaign showed Duffy with 42 percent and Lassa with 41 percent. The poll had a margin of error of 4.4 points. Ten percent of voters were undecided, and Independent Gary Kauther took 7 percent. The firm polled 504 likely voters Sept. 26 and 27.

“Both candidates have solidified their respective party bases,” the polling memo stated. “The race will be decided by voters whose preferences will not be driven by the question of which party controls Congress.”

Thirty percent of respondents said they did not care which party controls Congress.

A Public Opinion Strategies poll taken for Duffy’s campaign on Sept. 21 and 22, meanwhile, showed the Republican led 52 percent to 36 percent. POS surveyed 400 likely voters with a margin of error of 4.9 points.

Duffy will begin airing a new TV ad today. Lassa’s most recent ad started airing in the majority of the district on Sept. 21, the first day of Duffy’s poll. Her campaign contends the more voters learn about Duffy, the more they will move toward Lassa.

This has been one of the most hotly contested races in the nation. The Democratic Congressional Campaign Committee used its first independent expenditure ad in late August to target Duffy. The National Federation of Independent Businesses went up on radio in the district for the first time Tuesday.