But these days, as Republicans in Congress have made it clear that they have no intention of turning against Mr. Trump, Ms. Mace has quietly backpedaled into the party’s fold. Having once given more than a dozen interviews in a single day to condemn Mr. Trump’s corrosive influence on the party, Ms. Mace now studiously avoids the subject, rarely if ever mentioning his name and saying it is time for Republicans to “stop fighting with each other in public.”

After setting herself apart from her party during her first week in office by opposing its effort to overturn President Biden’s victory, Ms. Mace has swung back into line. She joined the vast majority of Republicans in voting to oust Representative Liz Cheney from leadership for denouncing Mr. Trump and his election lies. She also voted against forming an independent bipartisan commission to investigate the Capitol riot.

And rather than continuing to challenge party orthodoxy, Ms. Mace has leaned in to the most combative Republican talking points, castigating Dr. Anthony S. Fauci, the top health official who is a favorite boogeyman of the right, accusing Democrats of forcing critical race theory on children, and publicly feuding with progressives.