Now, in the face of primary challenges backed by the former president, the two have taken starkly different approaches to political survival. Ms. Mace has taken the teeth out of her criticisms of Mr. Trump, seeking instead to discuss her conservative voting record and libertarian streak in policy discussions. Mr. Rice, instead, has dug in, defending his impeachment vote and further excoriating Mr. Trump in the process.

Should they fend off their primary challengers on Tuesday, Ms. Mace and Mr. Rice will join a growing list of incumbents who have endured the wrath of the G.O.P.’s Trump wing without ending their political careers. Yet their conflicting strategies — a reflection of both their political instincts and the differing politics of their districts — will offer a look at just how far a candidate can go in their defiance of Mr. Trump.

In the eyes of her supporters, Ms. Mace’s past comments are less concrete than a vote to impeach. She has aimed to improve her relationship with pro-Trump portions of the G.O.P., spending nearly every day of the past several weeks on the campaign trail to remind voters of her Republican bona fides, not her unfiltered criticism of Mr. Trump.