Outgoing Gov. John Kasich (R-Ohio) on Wednesday endorsed Sen.-elect Mitt Romney (R-Utah)'s criticism of President Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE.

"Welcome to the fray, @MittRomney," Kasich wrote on Twitter, posting a link to Romney's Washington Post op-ed published on Tuesday.

Kasich is one of the Republican Party's most vocal Trump critics, openly blaming the president for the country's political divisions and slamming his hard-line immigration policies, which resulted in the separation of more than 2,000 migrant children from their parents at the U.S.-Mexico border.

ADVERTISEMENT

Kasich is known to be considering a run for president in 2020. He has said previously that a third-party candidate could have a "legitimate chance" in the upcoming presidential election.

Romney in the widely circulated op-ed wrote that he does not believe Trump has "risen to the mantle of the office," joining the ranks of Republicans who are publicly breaking with the president.

"I do not intend to comment on every tweet or fault," Romney wrote. "But I will speak out against significant statements or actions that are divisive, racist, sexist, anti-immigrant, dishonest or destructive to democratic institutions. To reassume our leadership in world politics, we must repair failings in our politics at home. That project begins, of course, with the highest office once again acting to inspire and unite us."

Another frequent Republican Trump critic, Sen. Jeff Flake Jeffrey (Jeff) Lane FlakeRepublican former Michigan governor says he's voting for Biden Maybe they just don't like cowboys: The president is successful, some just don't like his style Bush endorsing Biden? Don't hold your breath MORE (R-Ariz.), also tweeted a link to Romney's article, calling it "a thoughtful piece."

A thoughtful piece by incoming Senator Romney. https://t.co/pKO0wXgbLw — Jeff Flake (@JeffFlake) January 2, 2019

Some Republicans have rushed to the president's defense in the wake of Romney's comments, including Sen. Rand Paul Randal (Rand) Howard PaulGOP senator to quarantine after coronavirus exposure The Hill's Morning Report - Sponsored by National Industries for the Blind - Trump seeks to flip 'Rage' narrative; Dems block COVID-19 bill Overnight Health Care: Senate Democrats block GOP relief bill | Democrats reveal Medicaid chief's spending on high-paid consultants | Trump calls question about why he 'lied' about COVID-19 a 'disgrace' MORE (R-Ky.), who accused Romney of signaling "how virtuous he is in comparison to the President."

ADVERTISEMENT

“I wish Mitt could be more of a team player," Trump said on Wednesday, according to a pool report. "I endorsed him and he thanked me profusely."

Romney frequently criticized Trump in the run up to the 2016 presidential election. His comments came days before he will be sworn in to the Senate on Thursday.

"With the nation so divided, resentful and angry, presidential leadership in qualities of character is indispensable. And it is in this province where the incumbent’s shortfall has been most glaring," Romney wrote.