LOUISVILLE, Ky. (WDRB) -- Bruising. Nasty. Negative. Those are the words being used to describe the Republican U.S. Senate primary in Indiana.

The three GOP candidates have spent more energy attacking each other than going after incumbent Democratic Sen. Joe Donnelly.

The hostile tone was on full display Monday night in the final debate before next Tuesday's primary.

Congressmen Luke Messer and Todd Rokita and businessman Mike Braun all throwing punches in what has been a bare-knuckle brawl.

“You're going to hear lots of lies this evening because they have a poor record,” Braun said, pointing to his two opponents.

“It is a fact that independent fact checkers say Todd Rokita's campaign is mostly false,” Messer said.

“He doesn't even live in the state. He lives in the swamp,” Rokita responded.

Indiana University Southeast political science professor Joe Wert calls the race, “Close, competitive and kind of nasty.”

Wert said part of the reason is the three candidates are so close in the polls and on the issues.

“They have to sort of differentiate themselves in some other way,” Wert said.

The TV ads are also hitting hard as the three compete to win supporters of President Trump.

“President Trump was right. We need fewer career politicians in Washington,” said one Braun ad.

“I'll proudly stand with our president and Mike Pence to drain the swamp,” said Rokita in one commercial as he placed a “Make America Great Again” cap on his head.

Messer used a soundbite from Trump himself in one ad, as he and his mother endorsed the president’s agenda.

“I think it shows that, at least here in Indiana, that connection with Trump is still important,” Wert noted.

The Indiana seat is critical as Republicans try to hold on to Congress. But the primary winner will have the challenge of putting a fractured party back together for the fall.

“Whoever the eventual winner is will be able to unify the party, and come out with a pretty unified party in November,” Wert said.

Republicans are counting on party unity in the fall despite the lack of Hoosier hospitality in the spring.

Voters go to the polls in Indiana on May 8.

The Republican survivor can likely count on a lot of help from the president and from Vice President Mike Pence, the former governor of Indiana.

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