(The Hill) Joe Walsh, a former Republican member of Congress, said Tuesday he is becoming a Democrat, marking the end of his five-year streak as a political independent after leaving the GOP in 2020.

Walsh announced his formal affiliation with the Democratic Party in a Tuesday Substack post, saying he made the decision because he views the Republican Party as a threat to democracy and the rule of law and thinks defeating the GOP requires “a broad coalition of moderates, progressives, and, yes, even conservatives.”

“Three words I never thought I’d ever utter: I’m a Democrat. This former Republican Congressman, former Republican candidate for President, this former TEA Party champion is formally joining the Democratic Party. The stakes are simply too high to NOT become a Democrat,” Walsh wrote in his Substack post, before outlining his reasoning.

“Let’s start with the obvious—a tyrant sits in the White House. The very thing our Founders feared most is here. Throw in the fact that one of our two major political parties is a real and direct threat to democracy and the rule of law. These are unprecedented, dangerous times in America. I know it. You know it. There are even Republicans who know it,” he continued.

Walsh challenged Trump for the GOP nomination in the 2020 presidential race but dropped out after performing poorly in the Iowa caucuses. He quickly left the party and became a vocal critic of Trump, endorsing former President Biden in 2020.

Walsh has been unaffiliated for the last five years but said in his Substack post that Trump critics who are holding out hope for a third party are misguided.

“Without freedom, democracy, and the rule of law, America ceases to be. And currently, only the Democratic Party is on the side of all three of these core American values,” he wrote.

“There isn’t a third party coming to the rescue any time soon,” he continued. “Right now, the Democratic Party is democracy’s lone defender and best hope.”

Walsh acknowledged some issues with the Democratic Party but said “for democracy and the rule of law to persevere, Democrats must succeed” which necessitates becoming a “big tent” party and learning how to fight against Trump’s GOP.

“Take it from a former Republican fighter,” he wrote. “Republicans fight to the death to win politically, and they’ve always believed Democrats won’t. I’ve been a fighter my whole life, and if there’s ever been a moment when Americans are crying out for a Democratic Party with some fight, it’s now.”

He added: “And look, here’s the thing. We’re gonna need a HUGE tent to defeat this Republican Party. … We’re gonna need a Democratic tent big enough to hold both a conservative like Joe Walsh and a progressive like Alexandria Ocasio Cortez. I want to help build that big tent because I want to win, and … Trump’s Republican Party must lose.”

Walsh also reflected on his political and personal journey, saying he still is “a border hawk, an unabashed gun rights advocate, and an unyielding defender of free speech. But I’m not the same guy as I was 15 years ago, or even eight years ago.”

“I’ve opened my eyes and listened to people who don’t think like me,” he continued. “And by doing so, I gained a greater understanding of and appreciation for LGBTQ issues, structural racism, the need for empathetic immigration reform, the dangers of climate change, and the role government must play to help care for the neediest and most vulnerable among us.”

Walsh said he’s more compassionate and sees the importance of decency, tolerance, understanding and empathy in politics, saying only the Democratic Party “values and practices these traits.”

“Donald Trump is the worst of us, and, sadly, the rest of the Republican Party emulates his cruelty, dishonesty, and authoritarianism,” he continued. “We’re better than what we’ve seen every day these past four months. America is better than this. As a former Republican, I know that cruelty sells. Well, it’s time for decency to sell.”