Opinion | What in the World Happened to Elise Stefanik?

“She became a celebrity,” I was told by a Bush administration colleague of Ms. Stefanik’s who requested anonymity so this individual could speak freely about what is still a very sensitive subject. Until that point, this person said, “she hadn’t gotten fully on board the Trump train. Then she was put into first class, and she couldn’t get off. And first class is pretty plush.”

I reached out twice to Ms. Stefanik’s communications director, seeking comment from the congresswoman, but received no response. Ms. Stefanik, in defending herself, has argued that she’s reflecting the views of a majority of the people in her district, and she is. Mr. Trump carried her district by 14 percentage points in 2016. “I represent farmers, manufacturers and hard-working families who want someone who stands up for them, and President Trump spoke to those people,” she told Mr. Bannon on his show.

But even if you believe that the job of an elected representative is to vote according to the will of the voters rather than to owe voters one’s “judgment and conscience,” as the British parliamentarian and conservative political theorist Edmund Burke famously put it, at some point carrying out the will of the voters can become indefensible. That is certainly true if it requires a member of Congress to support a seditious president.

Looking at what happened with Ms. Stefanik is sad and disturbing because people who know her say she knows better. She was willing to be shaped by circumstances, even when circumstances drove her to ugly places and to embrace conspiracy theories. Contrast this with Ms. Cheney, who was stripped of her position in the Republican leadership and replaced by Ms. Stefanik. Ms. Cheney represents the people of Wyoming on many issues that are important to them, but she drew a line when it came to a fundamental attack on our democracy. She wouldn’t cross that line. Ms. Stefanik did.

Ms. Stefanik’s story is important in part because it mirrors that of so many other Republicans. They, like Ms. Stefanik, are opportunists, living completely in the moment, shifting their personas to advance their immediate political self-interests. A commitment to ethical conduct, a devotion to the common good and fidelity to truth appear to have no intrinsic worth to them. These qualities are mere instrumentalities, used when helpful but discarded when inconvenient.

The politicians and former Bush administration officials I spoke to were worried that Republicans in Congress will conclude that Ms. Stefanik’s path to power is the one to emulate. The fast track to leadership is to enlist figures like Mr. Trump, Mr. Bannon and what one of my interlocutors called “the army of the base,” made up as it is of QAnon followers, Christian nationalists, right-wing talk radio aficionados and those who are determined to overturn elections.