Senate candidate U.S. Rep. Luke Messer (R-Shelbyville) says he thinks the rhetoric in the GOP primary will calm down as his campaign officially begins.

The tone of the race to challenge incumbent U.S. Sen. Joe Donnelly (D-Ind.) has been marked by vitriol between Messer and U.S. Rep. Todd Rokita (R-Brownsburg).

Messer says now that his campaign officially gets underway, he’ll focus on substantive issues. He says that focus will decide the race, not what he calls “pre-announcement bickering.”

“I recognize the tone at the beginning of this campaign hasn’t been perfect,” Messer says. “Frankly, I didn’t pick this fight – I was sort of attacked by the guy that I’m running against.”

That “guy” is Todd Rokita, who shrugs off concerns about the race’s tone.

“Listen, we need the right candidate to go after Joe Donnelly. That’s what this is about,” Rokita says.

For his part, Joe Donnelly claims he’s not focused on what happens on the Republican side of the race.

“I think the best politics is to just work really hard, do my job, and stay focused on Indiana and that’s what I’m going to do,” Donnelly says. “And whatever happens on the other side will happen.”

The other Republican candidates in the Senate race are State Rep. Mike Braun (R-Jasper), businessman Terry Henderson, attorney Mark Hurt, and educator Andrew Takami.