Former GOP presidential nominee Mitt Romney said Friday he will vote for Texas Sen. Ted Cruz in an effort to block GOP front-runner Donald Trump from the nomination.

Romney, who has become the highest-profile member of the GOP’s emerging “Never Trump” movement, wrote in a Facebook posting that the race for the Republican nomination has become a contest between “Trumpism and Republicanism,” and urged the residents of his now-home state, and states beyond, to follow him in voting for Cruz.

Utah’s caucuses, scheduled for Tuesday, award convention delegates proportionally unless a candidate earns greater than 50% of the vote. The non-Trump vote is favored in the state, but is currently split between Cruz and Ohio Gov. John Kasich, who is spending Friday campaigning in Utah. Romney’s statement is designed to shift as many Kasich votes as possible to Cruz to help him ensure Trump doesn’t secure more delegates on a day when he is likely to win 58 in the winner-take-all Arizona primary.

Neither Cruz nor Kasich have a mathematical chance of reaching the 1,237 delegates required to win the nomination on the first ballot, and Romney explained that the name of the game is now keep-away, rather than shifting votes to a preferred candidate.

“The only path that remains to nominate a Republican rather than Mr. Trump is to have an open convention,” Romney wrote. “At this stage, the only way we can reach an open convention is for Senator Cruz to be successful in as many of the remaining nominating elections as possible.”

Earlier this month, Romney delivered an unprecedented speech by a party’s former nominee saying he believed Trump’s candidacy to be a danger to the country and called on Republicans to vote for whomever was best-positioned to take delegates from Trump. He spared no words in his critique of Trump Friday. “Through the calculated statements of its leader, Trumpism has become associated with racism, misogyny, bigotry, xenophobia, vulgarity and, most recently, threats and violence,” Romney wrote. “I am repulsed by each and every one of these.”

Romney, who campaigned in Ohio for Kasich on Monday, did not formally endorse Cruz, but encouraged all Republicans to vote for Cruz in hopes of forcing a contested convention. “A vote for Governor Kasich in future contests makes it extremely likely that Trumpism would prevail,” he wrote.

“I will vote for Senator Cruz and I encourage others to do so as well, so that we can have an open convention and nominate a Republican,” he added.

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