KINGSPORT, Tenn. — Inside the Kingsport Chamber of Commerce one morning last month, a few dozen voters sipped coffee and listened for 45 minutes to Representative Marsha Blackburn tick off all the reasons that this traditionally Republican stronghold in northeastern Tennessee should support her in one of the most high-stakes Senate races this year.

She praised President Trump. She warned of an invasion of liberal policies and a Democratic takeover of committees if Republicans lose the Senate. She stressed securing the border, fighting MS-13 and lowering taxes. She highlighted her work as a Republican House member to “get government off your back.”

But one issue was entirely absent — the one that had made Ms. Blackburn famous in Washington, and infamous in Democratic circles: abortion.

Even as the Supreme Court confirmation hearings for Judge Brett M. Kavanaugh have pushed Roe v. Wade to the forefront of American politics, Ms. Blackburn has largely relegated abortion to the background as she campaigns for the seat being vacated by Senator Bob Corker. Like other hard-right Republicans — including Brian Kemp, the candidate for governor in Georgia — she is adopting a broader platform, supporting Mr. Trump’s national agenda while focusing on statewide issues important to voters.