Former Fox News host Geraldo Rivera is turning his back on his longtime friend former President Donald Trump and will vote for Vice President Kamala Harris in the November election.

Rivera, who was a contestant on Trump’s reality TV show, “The Apprentice,” announced his decision Monday in a lengthy post on X, formerly Twitter, by calling the Republican presidential nominee a “sore loser” from the get-go, per Mediaite.

“With three weeks to go until Election Day, Donald J. Trump stands a reasonable chance of becoming the 47th President of the United States,” Rivera posted. “Despite assassination attempts, impeachments, special counsels, felony convictions and hundreds of millions in civil penalties, most polls show his race against V.P. Kamala Harris is too close to call.”

Rivera wrote about Trump’s meteoric rise from “novice to formidable challenger to victorious” in 2016.

“The first time he ran for president in 2016, he was coming off the last season of ‘Celebrity Apprentice.’ I had a front-row seat as a finalist on that final season and marveled at his audacity with his checkered past to seek the highest office in the land,” Rivera posted. “Then, in the blink of an eye, he went from novice to formidable challenger to victorious over Secretary of State Hillary Clinton.”

He continued recounting Trump’s time in office and his loss to President Joe Biden in 2020.

“As President he was a loyal friend, who allowed regular access. My resulting coverage gave him the benefit of most doubts. His presidency was underrated,” Rivera wrote. “Throughout his first big scandal in office, the 2017-2019 Mueller Investigation into allegations Trump conspired with Russia to undermine our political process, I stuck with him, deeply suspicious of constant efforts to undermine his Administration.”

He continued:

“The last time President Trump and I spoke was Friday, November 13, 2020, when he called me at home. It was ten days after his narrow lost to Joe Biden. He was calling to get my take on the controversies surrounding the election, which appeared to have been decided by a handful of votes in several states. I asked him what he would do if the vote count remained against him. As I reported on Fox News that same morning, Friday the 13th, he told me he was a reasonable man and would do the right thing if that time came.”

That time never came, Rivera wrote.

“Instead, President Trump embarked on an increasingly menacing campaign to discredit the 2020 election. With a motley supporting cast of increasingly fringe characters, he careened from one bizarre theory to the next, offering no meaningful proof, that he had been robbed by the Democrats,” Rivera wrote.

“None exists. If you are a Republican, Donald Trump has made a liar of you. He has coaxed and intimidated tens of millions into pretending he was reelected in 2020, and that the election was stolen.”

Rivera called that notion the “big lie” then wrote about the riot on Jan. 6, 2021.

“In furtherance of that Big Lie, on January 6, 2021, Trump incited and unleashed the violent attack on the center of democracy, the U.S. Capitol for which he was Impeached. As his followers trashed that sacred space, he was on the phone urging Vice President Mike Pence essentially to overturn the will of the American people,” Rivera wrote. “Pence refused to put Trump ahead of the Constitution. Trump stabbed the Constitution in the back.”

“Maybe you are inclined to vote for the former president anyway because he says he will cut your taxes or build the border wall or pull out of NATO or put tariffs on China. However, you justify voting for Trump, adopting his big lie about the stolen election makes you a liar,” he added.

He then made his plug for Harris.

“Better to admit he lost last time but that you don’t care because a Harris presidency would be a disaster, or you admire his defiance in the face of an assassin’s bullet,” Rivera wrote. “Just don’t pretend that he got robbed in 2020. That is a lie. Former President Trump is a sore loser who cannot be trusted to honor the Constitution. That is why I am voting for Kamala Harris to be our 47th President.”