Over the past two years, Justin Amash’s fans in the libertarian movement—that strange genus of political animal obsessed with individual liberty, free markets, and Austrian economist Friedrich von Hayek—couldn’t help but observe that the distinguished congressman from Michigan was getting noticeably jacked.

He wasn’t posing with dumbbells like __Paul Ryan__or bragging about his CrossFit routine like Donald Trump Jr. But libertarians pay attention to things like improved muscle mass—a manifestation, perhaps, of their relentless pursuit of self-reliance and self-improvement—and so inevitably Amash was asked about his routine. He’d started working out and improving his diet, he told people, and he’d become sort of addicted. By the time he held his infamous town hall in late May—the one in which he laid out his case for impeaching Donald Trump—his biceps had started bulging out of his shirtsleeves. Something was up, it seemed, and it didn’t take an Ayn Rand scholar to wonder whether Amash, now a muscle-bound gym rat, was working through some kind of breakup.

As it happens, around the time he started hitting the gym, Amash had begun agonizing over his relationship with the GOP. He was still a conservative, but the Republican Party had changed. In private, two people told me, he began floating the idea—quasi-seriously—about joining the Libertarian Party, and in public, he was barraged with questions about becoming their candidate (largely during interviews with the libertarian press). If ever his feelings were in doubt, they became even more clear after the Mueller report, when, on May 18, he became the only Republican to say Trump had committed impeachable offenses.

Amash’s first breakup was with the Freedom Caucus, the small but ferocious group of Tea Party congressmen who revived the practice of shutting down the government over budget fights, which he left on June 11. This was unsurprising to many, given Amash’s recent spate of media appearances criticizing the president. Fewer still were surprised when Amash engaged in a Twitter spat with the president’s son Don Jr. (“I hear Michigan is beautiful during primary season,” Trump Jr. wrote. Amash shot back: “If it’s what you say I love it especially later in the summer.”) Still, Amash’s next move came as something of a shock. In an op-ed in the Washington Post (on Independence Day, no less), Amash announced he was leaving the Republican Party altogether to become an independent.

Libertarians pride themselves on being guided by principle, not practicalities. Still, in political terms, Justin Amash had run off a cliff. So the question was where he planned to land. Those I spoke to agreed that the 39-year-old wasn’t ready to retire from the political arena, sinking into a tenured chair at the Cato Institute or taking a job complaining about Trump on cable news, like some of his former Tea Party peers. Speculation abounded in the libertarian world—and among the remnants of the Tea Party that had resisted the movement’s drift into Trumpism—that Amash might run for president, and maybe on their team. “He’s a very, very competitive SOB,” said Matt Welch, editor at large at the libertarian-leaning Reason magazine, citing his frequent Twitter clashes with Don Jr. (and Amash’s newly built revenge body).

For now, Amash is only running to keep his seat—but the election won’t be until 2020, and he faces threats both from Republicans, who are preparing to primary him, and Democrats, who now see an opening to score a seat in Western Michigan. And he might be blazing another path. Next week, Amash is scheduled to make a high-profile appearance at Freedom Fest, where libertarian activists—and more importantly, high-dollar donors—will convene. (His speaker bio does little to quell the rumors: “Will he? Won’t he?…One thing is for certain, we are looking for a presidential candidate that embrace principles of liberty to the MAX. Is Justin Amash the one?”)