Senator Jon Tester had been calling for stricter border security measures for years. So when President Joe Biden issued an executive order preventing migrants from seeking asylum if they illegally enter from Mexico at times when there is a high volume of crossings, Tester applauded. “I think it was a very, very good move,” he tells me, three hours after the announcement.

But the Montana senator did his hand clapping from his Capitol Hill office. Tester is a highly endangered species—the lone Democrat in statewide office in a deeply red state where Biden is unpopular and border security, Tester says, is the top election issue. So, like several other incumbent Democrats in tight races, Tester did not appear with Biden at the White House for the border policy speech. A spokesperson says he was tied up with Senate work; political reality was likely a factor too.

Almost no recent migrants crossing the southern border wind up in Montana. Yet the issue’s prominence in the minds of the rural state’s voters vividly illustrates how nationalized American politics have become, especially with Donald Trump on the presidential ballot. Tester, though, points to the local relevance. “Immigrants may not be coming, but fentanyl is coming into Montana, and it’s killing a lot of people,” he says.

Nuance, and a feel for what matters on the ground in Montana, come naturally to the 67-year-old. He is a fascinating mix of good ole boy and sophisticated, heterodox pol. At the age of nine, he lost three fingers on his left hand in a meat-grinding accident on the family farm. Tester, a trumpeter, got a music degree in college and taught the subject in the Big Sandy public schools before returning to work on the farm—which he eventually inherited, and where he still uses the same meat grinder but has shifted the crops to organic. In 1998, when a Republican neighbor decided not to run for reelection to the state senate, Tester jumped in.

He has stayed true to his old-school Democratic values even as Montana has swung to the right. To Tester, the Supreme Court’s Dobbs ruling was “the biggest reversal of personal freedom” in his lifetime. “Montanans,” he says, “don’t want a politician or a judge making their health care decisions.” He remains a fierce advocate for veterans and the middle class. “The middle class has helped power this country for nearly 250 years, and that can all change if you have the wrong people in leadership and they’re more concerned about themselves than they are the country,” Tester says. “Montana has seen an influx of people; some of them regular folks, others rich folks who are trying to buy the state and make it into where they came from. I like the old Montana, and I’m going to fight back.”

Indeed, the immigration wave that should most rattle native Montanans has been coming from California, Oregon, and Colorado, bringing gentrification and driving up real estate prices. Tester’s Republican general election opponent, Tim Sheehy, is a 38-year-old former Navy SEAL and current multimillionaire who moved to the state 10 years ago. He co-owns 20,000 acres, part ranch and part “lifestyle brand experience,” according to one magazine. Democrats are pushing hard to frame the Senate contest as a choice between authenticity and wannabe, between a third-generation brush-cut dirt farmer and a wealthy, photogenic newcomer. The first debate of the campaign is on June 9. “Sheehy is the archetype of what people in the state don’t want right now,” says Eric Stern, a senior adviser to two former Democratic Montana governors. “He bought this immense ranch, and he was charging people like 13 grand a pop to walk onto his property and go hunting. Twenty years ago, you just knocked on somebody’s door, and they usually said yes.”

Nobody likes increased prices. What’s harder to read and crucial to Tester’s chances are the political leanings of Montana’s thousands of recent arrivals: The state doesn’t register voters by party. “Some of the growth is good,” says Jim Messina, who worked as a strategist in the state, including for Tester, before managing Barack Obama’s 2012 reelection campaign. “But in general, when you think about why people move, it is probably more about taxes and crime, and those people tend not to be as Democratic. And we’re seeing this all over—Democrats are doing worse than traditionally with white voters.” According to Messina, the big question is, “Can Democrats win in deep red states in a presidential year? It’s going to be super fucking interesting.”

That’s one way to put it. Scary might be another. Retaining Democratic control of the Senate likely hinges on the reelection of Sherrod Brown in Ohio and Tester in Montana. That may be one reason, besides spite, that Trump recently mocked Tester for being fat. “When I look in the mirror, do I wish I was Charles Atlas? Yes,” Tester says with a laugh. “But Big Sky country is big guy country. And I don’t want to let the testosterone flow, but anytime Donald Trump wants to try to keep up with me picking up rocks or hay bales, I look forward to seeing if he can outwork me.”