INDIANAPOLIS – At Sunday’s televised debate of U.S. Senate candidates in the Republican primary, the three hopefuls were quick to start slinging mud at each other — and incumbent Joe Donnelly.

Will Baskin-Gerwitz, communications director with Donnelly for Indiana who watched the debate, said “It’s been a primary that’s been nasty, it’s been brutal and it’s been long.”

He said, “I think we got three candidates who spent the entire hour pretty much racing to the right. They were flip-flopping on positions they’ve held.”

Republican candidate Mike Braun said Social Security and Medicare are not being fixed by today’s politicians in Congress.

“We make those hard decisions,” Braun said. “You’re not gonna get that out of the people we’ve been sending to D.C. You need to get people who have lived it in the real world. You’re not gonna fix Social Security, Medicare or any of the other problems unless you do it.”

Donnelly’s team disputed Braun’s statement. Baskin-Gerwitz said, “Two months ago, all three of those candidates … they stood up on that stage and they pledged to cut Medicare, Medicaid and Social Security. That was only two months ago. If we’re to believe what we saw yesterday, all three of them have flip-flopped on something that’s pretty clear and core to their ideology.”

Another Republican candidate, U.S. Rep. Todd Rokita, that claimed health care reform legislation stalled because “we came one vote away from getting good reform for the next generation to the president’s desk. … Joe Donnelly stopped it from happening. That’s why Joe must go.”

Not true, said camp Donnelly. Baskin-Gerwitz said, “Joe Donnelly is the only candidate who’s going to protect Hoosier Social Security, Medicaid and Medicare.”

After Saturday’s strike on Syria, U.S. Rep. Luke Messer said the president showed strength in a measured way and then took a jab at Donnelly.

Messer said, “Contrast that with Joe Donnelly’s president, Barack Obama, who drew a line in Syria, then did nothing.”

Donnelly’s team fired back Monday. Baskin-Gerwitz said, “Joe Donnelly’s president is probably the same as Congressman Messer’s president. On Friday (when President Trump announced the strikes on Syria), Joe put out a decision swiftly applauding the president’s decision to take swift decisive military action with our allies in Syria. He asked and wanted to make sure we have a path forward and a stragegy.”

INDIANAPOLIS — As eyes across the country are watching how the Indiana Senate race unfolds, we dive into what makes it so important to the rest of the nation ahead of the Indiana Republican primary Senate debate hosted by WISH-TV on Sunday night. 

• Learn more about the candidates here.
• Have a question you’d like included in the debate? Submit it here. 

Laura Wilson, an assistant professor of Political Science at the University of Indianapolis, gave us some perspective leading up to the primary race.

“People are watching this race very closely because it’s seen as a very competitive one. The Democrats have 49 seats in the Senate; of course, our Joe Donnelly is one of those. Republicans are hoping to flip that,” Wilson said.

Among those Republicans hoping to shake up the Senate are businessman and former state Rep. Mike Braun, U.S. Rep. Todd Rokita and U.S. Rep. Luke Messer.

“There’s a lot of money being spent,” Wilson said. 

It’s all in hopes of flipping the seat from Democratic to Republican.

Wilson said U.S. Sen. Joe Donnelly is well aware the change is a possibility. 

“He wants to toe the party line, but he can’t be too close to that because of course that wouldn’t appeal to most Hoosier voters,” Wilson said.

Wilson said Donnelly’s advantage at this point is that he doesn’t have a primary contender.

“So he doesn’t really have to spend money right now,” Wilson said.

As for Rokita and Messer, Wilson said: “They’ve been in office for a while, so they have to say, ‘What have they done in the House of Representatives? Why should Hoosiers want to elect them now to the Senate versus just keeping them in the House?”

She said Braun’s challenge is different. 

“Making sure Hoosiers know who he is. Distinguishing himself from Rokita and Messer,” Wilson explained. “(Showing voters) why it’s good to have someone who isn’t already in Congress.” 

Political expert and former WISH-TV Statehouse Bureau Chief Jim Shella said we’re seeing the same thing we saw years ago — Republican candidates trying to “out-conservative one another” or prove they are the most conservative candidate. 

“I think a large part of that is because they’re looking at their base, the Republican party. Who’s going to show out for the primaries? That’s going to be very important. They have to do that right now. Without a doubt, a big challenge though, is whoever wins in May is going to have to make themselves more moderate come November,” Wilson explained.

Wilson said that last part could prove to be a difficult pivot later this year. 

According to Wilson, the candidates are making sure they appeal to their Republican primary voters now because they want to win that race but need to avoid isolating more moderate voters for the November general election.    

WISH-TV is your local election headquarters.

A live debate of the three Republican candidates for Indiana’s U.S. Senate seat will be broadcast Sunday on WISH-TV and Nexstar’s Indiana family of stations. The one-hour debate will begin at 7 p.m. Sunday. It also will air on WISHTV.com.

Who are businessman Mike Braun, and U.S. Reps. Luke Messer and Todd Rokita? Republican voters will chose one of them to try to unseat Democrat U.S. Sen. Joe Donnelly. The primary election is May 8. 

All three candidates went to the same small, liberal-arts college in central Indiana, Wabash College, in Crawfordsville. But after school, their lives took different routes.

Rokita serves the state’s 4th Congressional District. He has been elected to four terms in Congress. Before that, he served as Indiana’s secretary of state from 2003 to 2010.

Rokita and his family live near Brownsburg.

“I look forward to demonstrating who the real Trump ally is here.” Rokita has said. “I’m pro-life, I’m pro-Second Amendment and I’m pro-President Trump.”

Braun is the founder of Meyer Distributing and owner of Meyer Logistics headquartered in Jasper. He served in the Indiana House of Representatives from 2014 to 2017.

Braun is a Harvard Business School graduate. He and his wife live in Jasper.

Braun previously said, “I am looking forward to another debate to show Hoosiers which candidate is the true conservative and political outsider. We’re proving to Hoosiers everywhere that I am the conservative outsider who will defeat Joe Donnelly in November.”

Messer serves the 6th Congressional District. He has been elected to three terms in Congress. Before that, he served in the Indiana House of Representatives from 2003 to 2006.

A family man as well, Messer is from Greensburg. He also attended Vanderbilt Law School.

Messer has said, “We’re glad to be there when you guys conduct your debate, Frankly, I think voters will see through it if somebody decides they don’t want to show up.”

Editor’s note: Nexstar Indiana’s statewide political correspondent, David Williams, contributed to this story.