ABOARD JOE DONNELLY’S RV IN KOKOMO, Ind.—Joe Donnelly is the polar opposite of President Donald Trump in nearly every way.

On paper, he’s an ideologically centrist, mild-mannered, largely reserved Democrat. He doesn’t get into Twitter fights with his political enemies. He eschews the spotlight and rarely, if ever, goes on national television. He doesn’t care much for Trump’s bombastic personal style. He’s a throwback to the era when mundane was normal and voters rewarded the work and not the show.

But that was then. In modern political times, the landscape Donnelly faces is daunting. He is running in a state that Trump won big in 2016 and at a time when politicians seem preternaturally inclined to be bombastic. His task is to convince Indiana voters to re-elect him to the U.S. Senate. And his strategy is to convince them that moderation—in both temperament and ideology—is precisely what the country needs in these very immoderate times.

To do so, however, requires some strategic breaks from—and occasional rebukes of—the party he has called home his entire life. Aboard his RV on the last leg of a seven-day tour around the state, making his way from South Bend to Kokomo, Donnelly made clear that he felt Democrats had lost their political compass and that the evidence was in the drift of white working-class voters toward Trump.

“That’s who I work for, and that’s who Donald Trump talked to every day. And shame on the Democrat party for not talking to them more in recent years out here in the midwest,” Donnelly said in an interview sitting at the cramped kitchen table of his RV, which is decked out in campaign slogans and a blown-up photo of him waving and smiling.

The senator was at ease, rarely taking out his phone or allowing himself to become distracted inside the steaming-hot RV. At times he was outright defiant, his hands and fists often hitting the rickety table for emphasis.

It was only ten years ago that Hoosiers voted for Barack Obama during his first presidential run. But the state has moved rapidly toward the Republican party since then, and Trump won Indiana by nearly 20 points in 2016. (It helped that Mike Pence, his vice-presidential nominee, was a popular governor of the state at the time.)

Of the 10 Senate Democrats facing re-election this year in states where Trump defeated Hillary Clinton, Donnelly is considered to be one of the most vulnerable.

Faced with those odds, Donnelly has tacked to the middle. He often touts bipartisanship and notes that Trump has signed more than 20 of his bills into law, and that he has voted with Trump more than 60 percent of the time. He is also prone to paint the progressive wing of his party as fanciful. He does not abide by the notion that liberal populism can be sold to the white working-class voters that have drifted away from his party in recent years and, more recently, are solidly in Trump’s corner.

“You talk to folks in my state about free college and they go, ‘Oh, the teachers don’t get paid? The lights aren’t turned on? The building is free?’” he said with a laugh.

“There’s no such thing as a free lunch,” Donnelly said bluntly.

Donnelly’s fate is resting largely on a calculation that moderation can sell. Given Republicans’ razor-thin 51-49 majority in the Senate, control of that chamber could come down to whether he can successfully head off Mike Braun, a businessman and former state lawmaker who is running as a Trump loyalist.

Although Donnelly has joined all Democrats in opposing major legislative items of the Trump presidency—most notably the GOP tax bill and the unsuccessful attempts to repeal Obamacare—he remains an oft-courted vote for the White House. Earlier this week, Donnelly said he supports Trump’s demand for more border-wall funding as part of a deal to keep the government funded this fall. (Trump has threatened to shut down the government without that money.) Donnelly was also one of three Democrats to vote to confirm Neil Gorsuch to the Supreme Court, calling Gorsuch a “qualified jurist.”

That was a tough decision for Donnelly and his like-minded colleagues, Sens. Joe Manchin (D-W.V.) and Heidi Heitkamp (D-N.D.), who are aiming to win the backing of Trump voters in their states without alienating too many Democrats in the process. And now, they’ll have to do it all over again. On June 27, Justice Anthony Kennedy announced his intention to retire, and the reality set in for Donnelly that a potentially career-defining vote would be held before Election Day.

The senator said he was wrapping up interviews with local television stations when a reporter informed him about Kennedy’s retirement.

“I was like, ‘what?’ My heart didn’t sink, but I was like, ‘here we go again,’” Donnelly said.

He had a similar reaction when Chris Bogue, a voter who attended a meet-and-greet with the senator at Maple Farms here in Kokomo, asked him about his decision-making process on Kavanaugh.

“Aw man, I thought I’d be out of here by then,” he joked, prompting attendees to laugh, eventually telling Bogue that he was continuing to review Kavanaugh’s writings, court decisions and public speeches.

Bogue and her husband, Lannie, said in an interview that Donnelly’s vote on the Kavanaugh nomination will determine whether they vote to re-elect Donnelly in November. The senator later said he’s well aware of the bloc of voters, like the Bogues, who are withholding their support for him until and unless he votes for Kavanaugh.

“I would like to see him in. I don’t think you can get anybody smarter,” Lannie Bogue said of Kavanaugh.

Despite finding himself in a tough bind, Donnelly doesn’t give off the impression of a man particularly nervous. Wearing slacks and a blue button-down shirt, he jokingly rolled his eyes at the Kavanaugh question but rarely winced or sputtered when tackling dicey topics. At times, the mild-mannered senator even turned animated. His calculus on Kavanaugh, he stressed, was colored by the fact that the Supreme Court is set to hear cases on one of the top issues he has focused on throughout his political career: health care.

Speaking at a roundtable with constituents in South Bend, Donnelly praised the coverage requirements in Obamacare for people with pre-existing conditions. He said the Trump administration was “sabotaging” the Affordable Care Act, and he blasted the Justice Department for its apparent crusade to end such protections for people with pre-existing conditions, a legal battle that could end up before the high court.

Donnelly remains open-minded about Kavanaugh but stressed that he’ll press him on pre-existing conditions when they meet next week in Washington. Sitting next to his constituents, he went on a tear against the Justice Department “that once fought for civil rights” and is now trying to dismantle a popular provision of the Affordable Care Act.

Braun’s campaign declined an interview request for this article. But it is already clear that his strategy is to attack Donnelly for any break from the president, and to tie him to the national Democratic party apparatus as often as possible. That could include on Kavanaugh. And it already includes Donnelly’s vote against the tax cuts, which Braun and other congressional Republicans continue to argue are responsible for the current strength of the U.S. economy. Despite his inclination to find ground in the ideological center, Donnelly is remarkably, perhaps tellingly, unapologetic about that vote, explaining that it was an “easy” one because of how much money the legislation adds to the federal deficit over the next 10 years.

“Paul Ryan gave away the game when he said, we’ve got huge deficits, now we’re going to pay it down with Medicare and Social Security,” he said. “To see [those programs] be cut so we can give a tax cut to the very biggest corporations in this country, at the same time putting a huge debt on our children’s shoulders—I have no problem with that argument.”