LAWRENCE, Ind. — He has campaigned on his support for a border wall, railed against the “radical left,” and quoted both Donald Trump and Ronald Reagan in his campaign ads.

Joe Donnelly, trying to keep his Senate seat here in Indiana, may be a Democrat — but that’s not a word that comes up a lot as he campaigns.

“You have to run on a party, because you have to be on the ballot, in effect. But the night the election’s over, that’s over,” he said in an interview outside an early voting center last week, before deploying a line he likes to repeat. “I don’t serve as a Democrat senator or a Republican senator. I serve everybody in our state.”

Language like this has become a defining trait of Donnelly’s in this reelection campaign as he runs against Mike Braun, a businessman who has aligned himself with the president. Donnelly is one of five Senate Democrats running in a state that Trump won by double digits in 2016 — a 19-point victory here. Donnelly is trying to re-create the coalition of blue-collar workers and moderate Republicans in the “doughnut” counties surrounding Indianapolis that fueled his victory in 2012 and Trump’s four years later.

Donnelly — like Democrat Sen. Claire McCaskill in Missouri, who tried to separate herself from parts of her party by saying she’s not one of those “crazy Democrats” — has worked to distance himself from the far left of his party and embraced some of Trump’s policies.

During a recent debate, he said he was open to changing birthright citizenship, saying, “We have to take a look at that legislation.” He has also been a steadfast supporter of a border wall with Mexico, voting in favor of funding it three times and criticizing the upper chamber for failing to deliver the money for Trump’s signature proposal.

Donnelly voted with his party against the Supreme Court nomination of Brett M. Kavanaugh, but unlike Sen. Heidi Heitkamp of North Dakota — a Democrat running in a state Trump won by 36 points — he didn’t turn that into a fundraising boon. He raised $1.4 million in the first half of October. Heitkamp, whose “no” vote on Kavanaugh energized liberals, raised $12 million in the same period.

In the campaign overall, Donnelly has raised $16.1 million to Braun’s $17 million; the two are basically tied in the polls. The president and his surrogates, including Vice President Pence, who’s from Indiana, have visited the state to stump for Braun. That included a visit by the president Friday, when he said the Democrats want caravans “full of illegal aliens to flood into our country.”

Donnelly, in a statement on the rally, noted that he has voted with Trump 62 percent of the time and said, “I hope President Trump will return next year so that I can welcome him back to Indiana after I’m reelected on Tuesday.”

Donnelly is also getting help from high-profile Democrats, including visits from former vice president Joe Biden and, Sunday, one from former president Barack Obama.

Pete Buttigieg, the Democratic mayor of South Bend who gets mentioned as someone who could be on a presidential ticket, said the party is better for Donnelly’s presence in it.

“He’s got to appeal to a broad base, and it’s a healthy thing that our party has a lot of range in it and people who think for themselves,” Buttigieg said.

But, Buttigieg said, he wouldn’t look to Donnelly for leadership on progressive issues.

“One thing you learn quickly as mayor is you must not say one thing to one group that you would be embarrassed to have repeated to another, because you’re going to see everybody in the day,” he said.

Until recently, Indiana had a healthy crop of Democratic statewide officials and opted for moderate Republicans in the mold of six-term Sen. Richard Lugar, whom his successor, Donnelly, calls a “mentor.” The state voted for Barack Obama in 2008. But in 2016, Hillary Clinton won just three of Indiana’s 92 counties, while Trump won 56 percent of the vote.

Donnelly’s last opponent, in 2012, was tea party candidate Richard Mourdock, who pulled off a major upset by defeating Lugar in the GOP primary — but went into a tailspin after saying rape was “something that God intended” during the campaign. That set of circumstances yielded Donnelly a victory by 150,000 votes — and a reputation among colleagues of being an “accidental” senator. A win this year may be harder, both because of Braun’s candidacy and shifts in the state.

“This Senate race this year is important, because either it will identify this state as more Republican than it has ever been, or it will identify as it traditionally has been: centrist, moderate and given to split-ticket voting,” said Robert Schmuhl, professor emeritus of American studies at the University of Notre Dame, in South Bend. “It’s not clear what the anti-Washington, pro-Trump impulse will mean for Donnelly.”

Some voters reject Donnelly’s efforts to adopt stances from both parties.

“I’m wishy-washy, but I think politicians ought to be one thing,” said Susan Lucas, 74, a retired bank official and local museum director, a Republican who voted for Donnelly in 2012. “That’s what they claim to be at the beginning, ‘I’m a Republican’, so they should stick with the party.” She said was leaning toward voting for Braun.

Some accepted Donnelly’s bipartisanship as necessary in the context of an increasingly Republican state.

Michael Wilson, 40, a habitual ticket-splitter who owns a gourmet food store, said he’s going to vote for Donnelly because he opposes Trump. “There’s some things with Donnelly where I understand why he did what he did, I understand the choices he’s made, but I would have been a little bit uneasy,” he said. “Still, I think Donnelly’s done a good job. He’s in a tight spot.”

Others, however, said they were unsure where Donnelly’s support left him politically. Eric Sexton, a truck equipment salesman who intends to vote for Braun, said: “I don’t usually just vote Republican . . . but at this point I just want someone who’s Trump or not Trump. I want to see someone who promotes business and doesn’t create obstacles. I want to vote someone who’s going to be predictable; I don’t think voters need that unpredictable.”

Outside the early voting center, Donnelly appeared unperturbed by such criticism, saying bipartisan values were Hoosier values.

He said that, like Trump, he talks about jobs and issues that affect families and their ability to make ends meet. Again, he tied himself to the president, recalling a conversation with Trump on the president’s plane last September.

“He said, ‘I hear you’ll be real tough to beat.’ I said, ‘You bet, 100 percent, Mr. President, and here’s why. Those voters who voted for you, the union brick­layer, the fireman, the mom at home — before they were ever Donald Trump voters, they were Joe Donnelly voters, and in 2018 they’re Joe voters again,” Donnelly said.