Former Illinois Rep. Adam Kinzinger, an outspoken critic of Donald Trump and one of two Republicans to serve on the House committee investigating the Jan. 6, 2021, insurrection at the U.S. Capitol, endorsed President Joe Biden for reelection on Wednesday, charging that the former president is "a direct threat to every fundamental American value." 

What You Need To Know

  • Former Illinois Rep. Adam Kinzinger, an outspoken Republican critic of Donald Trump, endorsed President Joe Biden for reelection over the former president

  • Kinzinger was one of just 10 Republicans who voted to impeach Trump after the Jan. 6, 2021, insurrection at the U.S. Capitol

  • He voted for Trump in 2020 but began to speak out against his baseless claims of voter fraud after his loss to Biden

  • Kinzinger and former Rep. Liz Cheney of Wyoming were the only two Republicans to serve on the House Select Committee investigating the Jan. 6 attack

  • Earlier this month, Biden's reelection campaign hired Kinzinger's former chief of staff Austin Weatherford to lead outreach to Republican voters skeptical of Trump

In a video posted to social media, Kinzinger called himself a "proud conservative" who "always put democracy and our Constitution above all else," which led him to his decision to cross party lines and endorse Biden, a Democrat.

"My entire life has been guided by the conviction that America is a beacon of liberty, freedom and democracy," he said. "So while I certainly don't agree with President Biden on everything, and I never thought I'd be endorsing a Democrat for president, I know that he will always protect the very thing that makes America the best country in the world: our democracy."

“To every American of every political party and those of none, I say now is not the time to watch quietly as Donald Trump threatens the future of America,” said Kinzinger. “Now is the time to unite behind Joe Biden and show Donald Trump off the stage once and for all.”

Biden hailed the endorsement, writing in a post on social media: "This is what putting your country before your party looks like."

His campaign manager, Julie Chavez Rodriguez, said that they were "proud" to receive his endorsement, calling the ex-lawmaker "a true public servant who is a model for putting our country and our democracy over party and blind acquiescence to Trump."

"Congressman Kinzinger represents the countless Americans that Donald Trump’s Republican Party have left behind," she said in a statement. "Those Americans have a home in President Biden’s coalition, and our campaign knows that we need to show up and earn their support. President Biden will always fight for American democracy, for the rule of law, treating each other with decency and dignity and respect, and working to find common ground – even when we don’t agree with each other on everything."

Kinzinger served as a lieutenant colonel in the Air National Guard before he was elected to represent Illinois in the House of Representatives in 2010. Kinzinger voted for Trump in 2020, but began to speak out against his baseless claims of voter fraud after his loss to Biden.

He was one of just 10 Republicans who voted to impeach Trump after the Jan. 6 attack, and was part of a group of 35 members of the House GOP who voted to form an independent bicameral commission to investigate the insurrection. After Senate Republicans filibustered the independent commission, he was one of just two Republicans to support the formation of a House Select Committee to probe the attack, alongside then-Rep. Liz Cheney of Wyoming. He and Cheney both accepted then-House Speaker Nancy Pelosi's appointment to the panel, for which they were both censured by the Republican National Committee. Kinzinger also detailed receiving death threats amid his participation on the committee.

Kinzinger led two high-profile Jan. 6 committee hearings: one in which Justice Department officials detailed Trump's efforts to exert pressure on the department in his bid to overturn the 2020 presidential election, and one detailing Trump's inaction as the riot unfolded, alongside then-Rep. Elaine Luria of Virginia. 

Kinzinger did not seek reelection to Congress in 2022. He joined CNN as a commentator last year.

Earlier this month, Biden's reelection campaign hired Kinzinger's former chief of staff Austin Weatherford to lead outreach to Republican voters skeptical of Trump.

Trump and his allies have long dismissed Kinzinger's efforts to rally Republicans against him. The former president publicly celebrated when Kinzinger didn't seek reelection and has called for the prosecution of Kinzinger and others who served on the Jan. 6 committee, part of his pattern of suggesting his opponents face government retribution.

Biden has been particularly focused on courting supporters of Republican former presidential candidate Nikki Haley, who continued to win over a significant number of anti-Trump GOP primary voters throughout the spring even after suspending her campaign.

As part of Biden’s sustained outreach to moderate voters in both parties, his campaign released an ad highlighting Trump’s often-personal attacks against Haley, including his primary nickname of her as “birdbrain” and suggestion that “she’s not presidential timber.”

Haley said last month she will vote for Trump in November's election, though she reiterated her longstanding position that the Republican ex-president needs to earn the support of her voters.

The Associated Press contributed to this report.