She said she agreed with some of Mr. Braun’s positions on issues but would be sending a message by voting for Mr. Donnelly.

Another suburban woman, Linda Esposito, a self-described independent who is retired, agreed. “I feel like I need to make my vote about the Trump administration — his lack of professionalism, his lack of respect, his willingness to divide the country and calling the Democrats the mob. It’s ridiculous.”

She added, “No one can look up to the president anymore.”

Missy Shopshire, a business consultant, shares the other women’s negative view of the president and said, “It’s really hard to be a Republican and a conservative right now, and even harder to be a woman and a conservative.” But she said she would not let that affect her Senate vote. “The bottom line for me is what I believe the role of government is. I am a fiscal conservative, so I want to keep government small,” Ms. Shopshire said. She will support Mr. Braun.

While Mr. Donnelly talks of being bipartisan, Republicans are not obliging. Mr. Donnelly may have cited his work with Ms. Brooks in recently passed legislation to combat the opioid crisis, and at the Republican early vote rally in Anderson, Ms. Brooks said she indeed had a great partner in the Senate. Then she named the other senator from Indiana, Todd Young, a Republican.

Mr. Braun is making no virtue of bipartisanship. He defeated two Republican House members, Luke Messer and Todd Rokita, in the Senate primary, which in many ways was a contest of which man was the more enthusiastic backer of the president. He has billed himself as a version of Trump, with softer edges, having built a business that has made him extremely wealthy. He has tried to run as an outsider, wearing a signature deep blue, button-down collar shirt with no tie or jacket.