Peter Wehner worked in the George W. Bush administration. He knew Elise Stefanik when she was a moderate. Like others who knew her then, he is confounded by her transformation into a Trump lapdog/bulldog.

The lust for power does strange things to people. Compare Stefanik and Liz Cheney: Stefanik abandoned all principle to curry favor with Trump. Cheney gave up her powerful position and her political future by refusing to tolerate Trump’s assault on the Constitution and Trump’s lies. Cheney was the #3 House Republican before the failed coup; she was ousted by her colleagues and replaced by Stefanik.

Wehner writes:

There was a time in 2016 when Elise Stefanik, now the third-ranking Republican in the House, was so disgusted by Donald Trump, she would barely mention his name. Today he proudly refers to her as “one of my killers.”

She proved that again last month. In an effort to undermine confidence in the select committee investigating the violent assault on the Capitol, Ms. Stefanik said, “This is not a serious investigation. This is a partisan political witch hunt.” The committee, she said, is “illegitimate.” The hearings did not change her mind. In mid-July, before the final session planned for the summer, she referred to the committee as a “sham” and declared that “it is way worse than the impeachment witch hunt parts one and two.”

Maybe Ms. Stefanik was continuing to discredit the House committee because the evidence it has produced from Trump insiders — and the compelling way the evidence has been presented — has inflicted staggering damage on Mr. Trump, even though it might not prevent him from winning the Republican presidential nomination for a third straight time. Ms. Stefanik has failed in her efforts to sabotage the committee, but it’s not for lack of trying.

Ms. Stefanik’s fealty to Mr. Trump is so great that some of his advisers are mentioning her as a potential vice-presidential candidate if he runs in 2024, which he and his advisers are strongly hinting he will do.

The transformation of Ms. Stefanik, who is 38, is among the most dramatic and significant in American politics. Her political conversion is a source of sadness and anger for several people I spoke to who were colleagues of hers — as I was in the White House of George W. Bush although I did not work with her directly — and who were, unlike me, once close to her. To them, Ms. Stefanik’s story is of a person who betrayed her principles and her country in a manic quest for power.