– In an unsettled election year, Minnesota — where half the congressional seats are up for grabs as electoral maps shift from red to blue and blue to red — could be the state that tips the balance of power in the U.S. House.

Two Republicans hold seats in largely suburban districts where their party may be losing ground. Two Democrats are stepping down in outstate Minnesota districts that President Donald Trump carried decisively.

Come November, Republican majorities in the House and Senate will come down to a few key races. Minnesota could find itself swept up in a midterm Democratic wave, or it could be the bulwark where the GOP picks up seats and blocks that wave at the state’s borders. Many millions in political spending are expected to wash through the state in an election year that also features an open governor’s race, two U.S. Senate campaigns and dozens of other down-ticket races.

The stakes are high enough to mobilize activists and candidates across Minnesota. If Democrats retake the House, they will be able to bottle up Trump’s agenda while launching investigations into scandals that have dogged his presidency.

“I cannot have any real effect on Donald Trump, but I am represented in Washington by a person,” said Jena Martin, co-chair of Indivisible MN03, a progressive group that formed after Trump was elected.

That person, she believes, should no longer be U.S. Rep. Erik Paulsen of Eden Prairie, a Republican who represents a suburban district that Hillary Clinton carried — landing him on a shortlist of the most endangered incumbents in the country.

An energized base

For the past year, the 2,000 or so members of the local Indivisible chapter have gathered for events ranging from book groups to get-out-the-vote drives to protest, calling on Paulsen to hold a town hall.

“Our group has been focused on getting him to hold Trump accountable, and when he hasn’t done that, we let other neighbors know about his lack of backbone in standing up to Trump,” she said.

Paulsen pushed back against the idea that he is out of step with his district.

“The district’s no different than it was when I ran in other years,” he said. “President Obama won the district twice as well. Minnesotans ticket-split. They vote the person, not the party, and in the end they want someone who’s working on solutions.”

Activists have repeatedly picketed Paulsen’s office, questioning why he hasn’t held an open town hall in years. Paulsen said he has no plans during the midterm cycle to change his district outreach: open office hours, telephone town halls and private meetings with constituents and businesses. He said he did not want to “be shouted down by others who want to be boisterous or have other intentions.”

“I’ve got a lot of good things to talk about,” said Paulsen, who was on his way to a district event touting the suspension of an Obama-era medical device tax as part of the sweeping tax overhaul that Republicans passed at the end of last year.

Meanwhile, Dean Phillips, the wealthy Democrat seeking to unseat Paulsen, is crisscrossing the Third District in a mobile campaign office-slash-coffee truck, hoping suburban voters’ low opinion of Trump in numerous polls will extend to the GOP’s congressional majority. Minnesotans, Phillips said, are eager for common ground on divisive issues like health care, the environment and safe schools.

“I wouldn’t make the argument that this is becoming a blue district,” Phillips said. “What I would argue is that it’s one of the most thoughtful, most engaged districts in this entire country — and that means thoughtful Republicans and thoughtful Democrats and many independents, which is a hallmark of the Third District.”

But, he added, “I think there are some changes happening” in the Third. In addition to the women who jumped into political activism after the last election, Phillips said the days after the latest school shooting in Parkland, Fla., have brought a surge of young people into politics.

Similar dynamics animate the race in the neighboring Second District, where first-term Republican Rep. Jason Lewis is facing a rematch with DFLer Angie Craig in a mostly suburban and exurban district that Trump won by just 1 percentage point in 2016.

No safe seats

Political observers outside Minnesota are watching the state avidly.

“At the start of this two-year cycle, nobody, including me, thought the House would ever be in play,” said Jim Manley, a D.C.-based Democratic strategist and a Minnesota native. “For better or for worse, Democrats had gotten resigned to Republican control of the House.”

That attitude shifted after the election, as the activists who took to the streets to protest the inauguration showed up again to vote in special elections.

“Republicans in red districts across the country are losing these special elections,” Manley said. “There’s no such thing as a safe seat right now.”

But while special elections in other states have shaken up congressional and legislative maps — Alabama sent a Democrat to the U.S. Senate for the first time in decades and Republican control of the Virginia legislature came down to a coin toss — Minnesota’s special elections gave fewer clues to the electorate’s mood.

The race to replace two state lawmakers, one Democrat and one Republican, who stepped down amid sexual harassment allegations generated interest, excitement and cash but made no change in the balance of power in the statehouse. The Democrat was replaced with a Democrat and the Republican with a Republican.

“The Republican prospects in our state are the brightest they’ve been in over a decade,” said Minnesota GOP chairwoman Jennifer Carnahan, eyeing a best-case scenario where the party preserves its two endangered incumbent seats and picks up the two DFL seats left open by the gubernatorial bid of Rep. Tim Walz in southern Minnesota and the retirement of Rep. Rick Nolan in northeastern Minnesota. “Minnesota really is going to be at the forefront of elections during this midterm cycle.”

The 2016 election, when Trump carried all but nine of Minnesota’s 87 counties, gave Republicans hope that the state’s political landscape had shifted.

Rep. Collin Peterson has represented western Minnesota’s sprawling, largely rural Seventh District since 1991. He is the only DFLer running again in a district that Trump won. But a GOP state representative planning to challenge him dropped out last year, leaving the party for now without a top-tier challenger.

Still, Republicans see major opportunities in southern and northeastern Minnesota.

“We’re seeing a rejection of the Democratic Party because they’re at odds — the environmentalists, the animal rights people, they’re at odds with the farmers, they’re at odds with the union workers. They’re kind of in conflict with themselves,” said Jim Hagedorn, a Republican making his third bid to represent the First District in Congress.

The district has alternated between the DFL and GOP for the past 30 years. Now, Republicans like Hagedorn are hoping the district’s broad support for Trump in 2016 is sign that the district is swinging right again.

Foremost, Hagedorn said, is “pro-gun, pro-God, pro-life.” On those issues, he said, “the voters are solidly with us.”