Chicago (CBS) — Republican challenger for U.S. Senate Mike Braun has defeated incumbent Democrat Joe Donnelly in Indiana.

(Credit: CBS)

Braun, a multimillionaire auto parts magnate, is a strong ally of President Trump, in a state the president won by 19 points.

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“I’ve been animated by the belief that Hoosiers deserved better than the representation we’ve received from politicians in Washington, that people who have built their lives in the real world of business could create better lives for Hoosiers and Americans,” Braun said in a statement.

Donnelly had a target on his back ever since he unexpectedly won in 2012 after his opponent Richard Mourdock made incendiary comments about abortion and rape.

Donnelly was among a handful of Senate Democrats running for re-election in states President Trump won.

Trump was personally invested in Braun’s race, campaigning aggressively against Donnelly, who he called “Sleepin’ Joe.”

Ever since Trump’s victory, Donnelly has tried to walk a delicate line, celebrating areas where he agreed with the president while promising he won’t be a rubber stamp. Rarely does he mention that he’s a Democrat.

“If you want someone to be with a political party 100 percent of the time, I’m not that guy,” Donnelly said in his final ad of the campaign. “I’m not about party. Our politics are already too partisan and have become way too violent.”

But as the race tightened, he also adopted some of Trump’s rhetoric, angering members of his own party by attacking socialists and the “radical left,” while calling for a border wall with Mexico.

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Republicans say the first-term senator talks a good game. But they argue he has been against Trump when it counts, noting he opposed the GOP-led tax cut, legislation to repeal the Affordable Care Act and the confirmation of Supreme Court Justice Brett Kavanaugh.

“Career politicians like Joe Donnelly will say anything to keep their jobs,” Braun said.

With his party now poised to retake the House, Republicans have intensified their efforts to maintain or expand their narrow Senate majority, and Donnelly was viewed as one of their top targets.

More locally, the race offered a strong indicator of whether a conservative Democrat can still win in Indiana. The state elected Democrats in decades past to the governor’s office and a greater number of congressional seats. But after voting in 2008 for former President Barack Obama, who campaigned for Donnelly Sunday in Gary, Indiana has swung to the right.

Although insisting he’s a lifelong Republican, Braun voted in Democratic primaries for years, before switching over to the GOP before he was elected to his first of two legislative terms in the Indiana House.

Propelled by millions in loans that he made to his own campaign, Braun swamped Reps. Luke Messer and Todd Rokita with a wave of hard-hitting advertising.

Braun, who is worth somewhere between $37 million and $95 million, says Trump inspired him to run. If he wins Tuesday, it will be after similarly running on a similar template as an outsider businessman.

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“He didn’t need this. I didn’t need it either, by the way,” Trump said at a rally for Braun near Indianapolis last week. “But we’re having fun. You know why? We’re winning.”