Dan Feehan, an Army veteran and former teacher, announced Tuesday he will challenge first-term Republican Jim Hagedorn, setting up a rematch of last year’s southern Minnesota congressional race that the Democrat lost by a narrow margin.

Feehan wasted no time opening up attacks on Hagedorn as “beholden to special interests and a political party,” previewing in an interview what is likely to be a long, negative and expensive campaign. The contest will be one of the most closely watched in the country to see if Republicans can hold their base in the face of a struggling farm economy and the impeachment inquiry of President Donald Trump.

Hagedorn defeated Feehan in 2018 in the First Congressional District by about 1,300 votes out of more than 190,000 cast. Hagedorn’s victory came despite being outspent by the Democrat by a margin of $4.1 million to $1.6 million, according to the Center for Responsive Politics, which tracks campaign spending. Spending by outside groups on both sides exceeded $14 million.

The National Republican Congressional Committee released a brief statement Tuesday saying voters had rejected Feehan’s agenda in 2018 and would do so again in 2020, attempting to draw a connection between Feehan and more progressive Democrats who favor a “Medicare for All” insurance system, a decriminalized border, legal late-term abortion and mandatory buyback of certain assault-style rifles.

The First Congressional District, which runs the length of southern Minnesota, is anchored by Rochester and Mankato. Although Gov. Tim Walz represented the district for 12 years as a Democrat, it leans Republican, having given President Donald Trump a 15-percentage-point victory margin in 2016.

Trump visited Rochester for a rally in 2018 to help Hagedorn, and he’s likely to loom large again in the 2020 contest. Feehan deflected questions about Trump, saying he would build on his 2018 campaign theme of “an independent voice in Washington not beholden to special interests or a party.”

Feehan said he’s concerned that an impeachment inquiry into Trump will be overly partisan and distract from important policy issues like health care and the farm economy.

Still, he allowed, “As someone who has sworn an oath to support and defend the Constitution, I’m deeply concerned about what unfolded,” adding, “I’m deeply concerned [Hagedorn] is not taking it seriously.”

For his part, Hagedorn is trying to rally Trump supporters, using a recent fundraising letter to call the impeachment inquiry “more nonsense from the radical resistance Democrats.”

The Hagedorn letter continued: “Instead of joining Republicans and working to pass the United States-Mexico-Canada trade deal, a transportation and infrastructure bill, reform of the generic drug process, common sense border security and other measures, they play political games and further alienate themselves from the majority of voters.”

Feehan won a Bronze Star in the war on Iraq and was deputy assistant secretary of defense in the administration of President Barack Obama.

Since his 2018 defeat he’s been a consultant to the Farmer’s Union, an agriculture group that leans toward the DFL, helping develop programming for struggling farmers.

“I’m trying to work with them to build resilience in farming communities,” he said. Feehan said farmers he talks to have had a difficult planting season and are losing patience with Trump’s trade war with China, which has threatened export markets.

He has two children and he and his wife are expecting their third child in November.