Weld made a similar call for Trump’s resignation during an appearance on MSNBC’s “The Last Word” on Tuesday.

“If Donald Trump is an American patriot, he should resign from office,” the GOP challenger wrote in the opening of his editorial.

An outspoken critic of Trump, Weld offered an even stronger rebuke in an op-ed for The Bulwark , a conservative political commentary site, published Wednesday.

“For the good of the country, if he [ @realDonaldTrump ] had the self awareness that Richard Nixon did, he would resign” tonight on @TheLastWord with @Lawrence #Weld2020 #fitn #nhpolitics #iapolitics

Weld is the first Republican to challenge Trump for the Republican nomination, and he’s the first Republican to challenge an incumbent president in the same party since Pat Buchanan challenged President George H.W. Bush in 1992.

Weld announced his candidacy earlier this month during an appearance on CNN, where he called six more years of the Trump administration a “political tragedy.”

Weld focused mostly on the details revealed in the redacted report from special counsel Robert Mueller, which Trump initially said exonerated him of any criminal wrongdoing, then later claimed statements in the investigation on Russian interference in the 2016 campaign were “fabricated & totally untrue.”

“Trump claimed with his usual arrogance and ignorance that he has been vindicated,” Weld wrote in the op-ed. “In truth, the Mueller report revealed that Trump is a one-man crime wave.”

Weld repeatedly referred to Trump as a liar and accused him of using the “power of the Oval Office to protect himself and his associates from the consequences of their actions.”

The former governor said the only protection Trump had from becoming a criminal is the intervention of his White House aides “who derailed his criminal conspiracies by distracting the president, or simply ignoring him.”

In the redacted report, Mueller’s team said they didn’t find sufficient evidence that Trump’s presidential campaign conspired with the Russian government during the 2016 election. However, the report also didn’t exonerate Trump from accusations of obstructing justice by interfering with Mueller’s investigation. The special counsel looked at 10 instances in which Trump may have obstructed justice, but Mueller declined to make a determination on it.

“Fortunately, Bob Mueller was able to do his job despite Trump’s constant interference,” Weld wrote in The Bulwark. “But it is worth noting that those aides who pushed back against Trump’s worst instincts have since been pushed out of the White House.”