Former Republican congressman Joe Walsh says he voted Trump in 2016, but you wouldn’t know it from his Twitter TWTR, +1.62% feed lately:

If Walsh’s relentless Trump-smashing on social media isn’t enough to convince you that he’s had a change of heart, his scathing editorial published in the New York Times NYT, +0.19% on Wednesday should do the trick:

“ ‘Mr. Trump is a racial arsonist who encourages bigotry and xenophobia to rouse his base and advance his electoral prospects. No matter his flag-hugging, or his military parades, he’s no patriot.’ ”

Those are just some of the justifications Walsh used to make the case that Trump should face a Republican primary challenger in the coming election.

“At the most basic level, Mr. Trump is unfit for office,” he continued. “His lies are so numerous — from his absurd claim that tariffs are ‘paid for mostly by China, by the way, not by us,’ to his prevarication about his crowd sizes — he can’t be trusted.”

Walsh also talked about why Trump earned his vote in 2016.

“I voted for him because he wasn’t Hillary Clinton. Once he was elected, I gave him a fair hearing, and tried to give him the benefit of the doubt,” he wrote. “But I soon realized that I couldn’t support him because of the danger he poses to the country, especially the division he sows at every chance, culminating a few weeks ago in his ugly, racist attack on four minority congresswomen.”

Walsh says a challenge from the right would be more formidable than from the current crop of candidates on the left.

“A majority of Americans want fixes to our most basic problems,” he wrote. “We need someone who could stand up, look the president in the eye and say: ‘Enough, sir. We’ve had enough of your indecency. We’ve had enough of your lies, your bullying, your cruelty, enough of your insults, your daily drama, your incitement, enough of the danger you place this country in every single day.”

Walsh noted that former Massachusetts Gov. Bill Weld, who ran with Gary Johnson on the Libertarian Party’s 2016 presidential ticket, is challenging Trump ‘from the center,’ though he’s considered a real long shot.

Here’s Weld talking about the prospects of a debate with Trump:

As for Walsh’s editorial, it was met with the expected batch of mixed reviews: