– On one side of the local high school, Joe Radinovich shook hands with teachers. On another floor of the building, Pete Stauber was finishing up a tour of his own. The candidates in one of the country’s most competitive congressional races both looked relaxed at Grand Rapids High School earlier this week, even after weeks of increasingly heated rivalry.

For months, Radinovich, the Democrat, and Stauber, the Republican, have crisscrossed northeastern Minnesota’s sprawling, 27,000-square-mile Eighth Congressional District, trying to win over voters in a race that’s become a test for whether Democrats can hold on in districts won two years ago by President Donald Trump.

It’s one of the races that could help determine which party controls the House next year. That’s prompted a slew of TV attack ads, about $9 million in outside spending, national media attention and visits from Trump and Vice President Mike Pence.

Campaigning on the Iron Range this week, Stauber and Radinovich tried to appeal to the district’s working class voters. Stauber, a St. Louis County commissioner and retired Duluth policeman, and Radinovich, a former state legislator and Democratic strategist, touted themselves as blue-collar leaders who can work in a bipartisan way to represent the massive, politically diverse district. Both support mining and vow not to cut Medicare and Social Security, even as top Republican leaders suggest cuts to entitlements to deal with the rising national deficit.

That’s a big issue for the Eighth District, with the highest median age and highest number of adults who are 65 years old and older.

The district’s largest city, Duluth, has seen its population level off, while places like Chisago County and Grand Rapids are growing.

The district, which spans 18 counties from the Twin Cities exurbs to the Canadian border, has seen mining and logging jobs shrink.

Radinovich often cites a statistic: 14,500 Iron Range miners produced 40 million tons of ore in 1980, and 4,500 miners now handle the same amount.

“Our economy has shifted,” said Mary Drewes, 76, a retired social worker from Coleraine near Grand Rapids. “I think this [race] is real critical.”

For 64 years, Democrats held the Eighth District seat. Then in 2010, voters replaced Jim Oberstar with Republican Chip Cravaack.

Two years later voters swung back to the DFL, electing Rick Nolan; he was narrowly re-elected in 2016 by 2,009 votes — even as Trump carried the district by 16 percentage points.

Now Republicans see the Eighth as one of their best chances nationwide to flip a Democratic seat. Trump’s PAC, America First Action, is spending more than $1 million in the final days on Stauber, on top of $1.9 million already spent.

“It’s a high priority pickup [seat] for the Republicans,” Stauber said, sitting in a black passenger van wrapped in a photo of him.

Stauber, 52, fits the part of a northern Minnesota politician, a former pro hockey player and one of six boys in his family who all played hockey. He often tells the story of surviving a bullet to the forehead in an off-duty incident and having a gun pointed at him on duty.

His wife, Jodi, is a veteran and the couple have four children, including a son with Down syndrome. Stauber featured his son in an ad talking about why he supports making sure health insurance covers pre-existing conditions — a protection that Republicans in Congress voted multiple times to undo in recent years.

While he’s a staunch Trump supporter, Stauber also calls himself a pro-union Republican. He said he’s not in favor of repealing and replacing the Affordable Care Act, saying he’d rather work to improve it.

“I won’t blindly follow anybody,” Stauber said.

Nancy McReady, 64, of Ely, said she was a Democrat but grew frustrated with the party in the 1990s. Now she’s a Stauber supporter, against single-payer health insurance and fearful about immigration, citing a Central American caravan in Mexico.

“It’s going to hit our taxes at some point,” said McReady, wearing buttons that read “hug a Ranger” and “vote jobs.”

Radinovich, 32, grew up in Crosby, and hails from a family with fourth-generation roots on the Iron Range. Wearing jeans and a suit coat for another day on the trail, Radinovich was greeting miners in Virginia by 5:45 a.m. before trekking to Grand Rapids for the school tour. He walked through the cafeteria filled with students, and a group of kids cheered. “Holy crap, it’s Joe Radinovich,” a boy said.

“I’ve never seen anything like that,” Radinovich said of the attention, adding: “That’s what happens when you have $7 million of ads against you.”

Ads by national Republican groups have cited a number of parking and speeding tickets against Radinovich, and a misdemeanor drug paraphernalia charge for marijuana as a teen.

Radinovich has taken to talking about tragedy in his life: his mother was killed in a murder-suicide when he was a teenager, and another family member nearly died in an attempted suicide.

“What I know is that my struggles have made me stronger,” Radinovich said in a recent online video meant as a response to attack ads. “They’ve given me a deeper understanding of what community is about, and what’s at stake in this election.”

Radinovich recalled his mother’s death when explaining why he supports gun violence prevention measures such as a ban on high capacity magazines and bump stocks, in a part of the state where hunting is a major pastime.

Hours after both men passed through Grand Rapids High School, they met again in Chisholm. A couple hundred residents packed the final debate of the race, which included the third candidate, Ray “Skip” Sandman of the Independence Party.

Before it started, Radinovich greeted his fiancé, Carly Melin, a former state representative from Hibbing.

“My opponent hasn’t offered one single idea on health care. ... He seems either dangerously uninformed about this topic or without a plan of his own and subject to the whims of the Republican majority in Congress,” Radinovich said.

He added later that Stauber may support things like broadband access and workforce development, but hasn’t said how he’d pay for it.

Radinovich also questioned Stauber’s honesty. That day St. Louis County released e-mails Stauber wrote using his county address to send messages concerning his candidacy, despite a county code of conduct that says elected officials shouldn’t do that.

Stauber said his law enforcement career means he can handle tense situations, and touted his support for mining and Enbridge’s oil pipeline project.

“We should be the economic engine of Minnesota’s Eighth Congressional District,” Stauber said.

Stauber has attacked Radinovich for having “limited life experience” and a “criminal record,” and said he has “zero credibility” after his vote in the Legislature supporting the creation of MNsure, Minnesota’s vehicle for delivering the Affordable Care Act.

“It’s going to be really, really close,” said Mike Rootes, 45, of Hibbing, who works as a maintenance mechanic at Hibbing Taconite Company. Like his steelworkers union, Rootes will support Radinovich, though he said his co-workers are becoming more evenly split between Republicans and Democrats.

“Trump kind of spoke to some people who didn’t have political interest before,” he said.