itt romney is leaning forward in his chair, his eyes flashing, his voice sharp.

It’s a strange look for the 72-year-old senator, who typically affects a measured, somber tone when discussing Donald Trump’s various moral deficiencies. But after weeks of escalating combat with the president—over Ukraine, and China, and Syria, and impeachment—the gentleman from Utah suddenly appears ready to unload.

What set him off was my recitation of an argument I’ve heard some Republicans deploy lately to excuse Trump’s behavior. Electing a president, the argument goes, is like hiring a plumber—you don’t care about his character, you just want him to get the job done. Sitting in his Senate office, Romney is indignant. “Are you worried that your plumber overcharges you?” he asks. “Are you worried that the plumber’s going to scream at your kids? Are you worried that the plumber is going to squeal out of your driveway?” I am playing devil’s advocate; he is attempting an exorcism.

To Romney, Trump’s performance as president is inextricably tangled up in his character. “Berating another person, or calling them names, or demeaning a class of people, not telling the truth—those are not private things,” he says, adding: “If during the campaign you pay a porn star $130,000, that now comes into the public domain.”

At this, Romney glances over at two of his aides who are watching silently from the other end of the room, and grins. “They’re going, Oh gosh, shut up.”

I’ve spent the past several months in an ongoing conversation with Romney as he’s navigated a Washington that grows more hostile by the day. Before arriving in the Senate, Romney nurtured a pleasant delusion that he could somehow avoid being defined by his relationship with Trump. He had his own policy agenda to advance, his own vision for the future of the Republican Party. He would use his platform to take a stand against Trumpism, while largely ignoring Trump himself. When I would speak with his friends and allies in Utah during last year’s campaign, there was often a certain dilettantish quality in the future Senator Romney they envisioned—a venerable elder statesman dabbling in legislation the way a retiree takes up tennis.

Instead, Romney has emerged as an outspoken dissident in Trump’s Republican Party. In just the past few weeks, he has denounced the president’s attempts to solicit dirt on political rivals from foreign governments as “wrong and appalling”; suggested that his fellow Republicans are looking the other way out of a desire for power; and condemned Trump’s troop withdrawal in Syria as a “bloodstain on the annals of American history.”

Trump has responded with a wrathful procession of personal attacks—deriding Romney as a “pompous ass,” taunting him over his failed presidential bid in 2012, and tweeting a cartoonish video that tags the senator as a “Democrat secret asset.”

These confrontations have turned Romney into one of the most closely watched figures in the impeachment battle now consuming Washington. While his fellow Republicans rail against “partisan witch hunts” and “fake whistle-blowers,” Romney is taking the prospect of a Senate trial seriously—he’s reviewing The Federalist Papers, brushing up on parliamentary procedure, and staying open to the idea that the president may need to be evicted from the Oval Office. Read more at The Atlantic