Former state senator and lieutenant governor Michelle Fischbach announced Monday that she will challenge a Democrat stalwart, U.S. Rep. Collin Peterson, for the Congressional seat in Minnesota's western Seventh District.

Fischbach will be a formidable opponent for Peterson, a 15-term congressman who has defeated a string of poorly funded Republican candidates even as his district has grown more conservative, said Sam Winter, a spokesman for Fischbach's campaign.

"It is the most pro-Trump district in the country held by a Democrat," said Winter, noting that Peterson won re-election in 2018 even though the Republican president carried his district by 31 points in 2016.

Fischbach seized on the president's popularity in her written announcement, and highlighted Peterson's voting record in opposition to President Donald Trump's administration.

"One of his first votes this Congress was to ban the wall, and he votes against President Trump 85 percent of the time," she said. "Unlike Peterson, I will work with President Trump to secure our borders, build the wall, fight against the Democrats' socialist agenda and keep America great."

A call and an e-mail to Peterson's campaign office was not immediately returned Monday night. As chairman of the House Agricultural Committee, Peterson has maintained popularity and strong support from farmers and rural voters in his district.

Peterson is considered a Blue Dog Democrat with conservative positions on abortion and same-sex marriage. He voted against the Affordable Care Act that was championed in 2010 by his own party and President Barack Obama, but also against Trump's legislation in 2017 that would have repealed it.

Winter acknowledged the oddity of making a campaign announcement on Labor Day, but said Fischbach would be following up all week with a series of media interviews and visits across the district, which stretches from the Northwest Angle of Minnesota down to Pipestone in the southwest.

Fischbach lives in Paynesville with her husband, Scott Fischbach, executive director of the anti-abortion organization Minnesota Citizens Concerned for Life. Fischbach built a strongly conservative and anti-abortion track record in her long career in state politics, starting with her election to the Minnesota Senate in 1996, and her selection as the state's first female Senate president in 2011.

In a political oddity, she was advanced to the position of lieutenant governor for Gov. Mark Dayton, a Democrat, in January 2018 when her predecessor, Tina Smith, resigned to fill a U.S. Senate vacancy. Fischbach at first attempted to maintain her state Senate role as well, prompting a political and legal dispute that ended in May 2018 when she resigned that post and was sworn in as lieutenant governor.

Rumors earlier this year of Fischbach's candidacy were tamped down when she accepted a position with the Central Minnesota Builders Association. Buzz resumed last month when her husband promised "breaking news" on his Facebook page, but that turned out to be the birth of their fifth grandchild.

Jeremy Olson • 612-673-7744