COMMENTARY: Independent thinker or rubber stamp for U.S. Senate?

"If you look at my record, I've done that when I was in the state legislature," he said at this week's U.S. Senate debate. "I've done it in my business. A record speaks for itself."

That claim might have come as a surprise to anyone who was paying attention during Braun's primary election campaign against two Republican congressmen, Todd Rokita and Luke Messer. In that contest, the three candidates tripped all over themselves trying to earn recognition as the candidate most likely to support President Donald J. Trump. 

And, for the most part, Braun has stood by that strategy. In interviews with reporters, he has declined to list even a single issue on which he might part ways with the president.

"I'm going to be an ally that Donald Trump can count on every time," he said in a fundraising letter.

His opponent, Democratic U.S. Sen. Joe Donnelly, says the president can count on him, too. Sometimes.

"People ask me, 'Joe, what do you think of President Trump?'" he says in a campaign ad. "It's simple. When he's for Hoosiers, I'm with him. When something's bad for Hoosiers … I won't go along with any president."

Braun describes Donnelly as a man without convictions.

"He never sticks his neck out," Braun said at the debate. "He blows with the wind."

He has also accused Donnelly of voting in lock step with the Democratic leadership.

"Sen. Donnelly says he's in the middle, but he's not," Braun says in a campaign ad. "He votes with Chuck Schumer, endorsed Hillary Clinton and stands with the extreme left 80 percent of the time. That's not common sense. It's just another career politician who will say anything to keep his job."

ProPublica and Braun quote a similar percentage. ProPublica says Donnelly split from his party on more than one in five votes in the current Congress, but the organization also says Donnelly's record qualifies as the third-highest defection rate among members of either party.

That's an image Donnelly embraces.

"I go against my party all the time," he said during the debate. "I've been with the president 62 percent of the time. That's what we're supposed to do."

As for Braun, a review by The Indianapolis Star found that of the more than 1,400 votes he cast during his three-year stint in the Indiana House of Representatives, only 22 strayed from the party line.

He cast one of those 22 votes as one of six Republicans who opposed a measure establishing HIP 2.0, the program Indiana used to expand Medicaid under Obamacare. 

Attitudes on Obamacare have shifted. The vote Donnelly cast to save the law was once the fodder of Republican attack ads. Now, he brags about it.

"I stand here proudly before you and all the people of Indiana to tell you I was the deciding vote that saved coverage for pre-existing conditions," Donnelly said during the debate.

He charged that Braun, on the other hand, had supported a GOP-led lawsuit aimed at eliminating the law. Braun doesn't deny that, but he insists he would replace the law with a measure that would cover pre-existing conditions.

All in all, Braun is betting Hoosiers want a senator who will stand with the president every time, and Donnelly is betting they want a guy who will be a bit more independent.

Two years ago, President Trump carried Indiana by 19 percentage points. Now, polls indicate the numbers are shifting.

Have they shifted enough for Donnelly to keep his seat? We'll find out Nov. 6.