President Donald Trump invited outgoing congresswoman Haley Stevens, a longtime Michigan Democrat, to join the Republican Party after she surprisingly endorsed her state’s GOP nominee for the U.S. Senate, Mike Rogers, in a last-minute move her partymates have called a “betrayal.”

“I don’t know Haley, I’ve never met Haley,” Trump said at a rally in Iowa on Sunday, the final weekend before the Nov. 3 midterm elections. “But Haley said what few people are willing to say. I think I’d probably—I’d love her to join the Republican Party actually.”Stevens ran for the U.S. Senate seat herself but lost the Democratic primary to progressive Abdul El-Sayed in August. While she initially congratulated and offered her support to El-Sayed for the general election, the two have been at odds, primarily over concerns about antisemitism, which Stevens has accused El-Sayed, who is Muslim, of not denouncing strongly enough.

On Friday, Stevens demanded that El-Sayed denounce a controversial ad that blamed Michigan’s cost-of-living issues on U.S. aid to Israel. El-Sayed, whose campaign was not behind the ad though it supported his candidacy, responded with a statement that the focus of his campaign is on the “challenges Michiganders are facing” and defeating Rogers, while Stevens “seems intent on relitigating a primary that ended three months ago.”He told reporters that he did not agree with the ad’s contents but did not want to “play the condemn game” about an unaffiliated ad.

Stevens was supposed to appear with El-Sayed at a planned Democratic campaign event on Sunday, but Rep. Debbie Dingell (D, Mich.) said in an interview that before the event, she disinvited Stevens on account of her strained relationship with El-Sayed. “There’s nothing to be gained by the two of them being in the same place,” Dingell said Saturday.

On Sunday, Stevens appeared instead at an event at Perfecting Church in Detroit with Rogers. “Our Democratic nominee for Senate, Abdul, said I was no longer welcome in his campaign and that I should stay away,” Stevens said in a video posted on social media later that morning. “And he’s right. And that’s why I am endorsing Mike Rogers for the United States Senate today.”On CNN on Sunday night, Stevens attempted to explain her move, saying it was because of El-Sayed’s “anger and lack of kindness.”

She cited his past associations with controversial political influencer Hasan Piker and Piker’s uncle Cenk Uygur, whose Rebellion PAC was behind the recent anti-Israel ad. She insisted that she is “trying to help” the Democratic Party by turning on El-Sayed, whom she compared to Graham Platner, the former scandal-plagued Democratic nominee for U.S. Senate from Maine who withdrew from that race in July.

Stevens said she remains a “really proud Democrat” who “absolutely” wants Democrats to win control of the Senate, but her shock announcement of an endorsement for the GOP candidate just days before Election Day could upend a tight race that may decide the fate of the upper chamber.

Democrats denounce, Republicans pounce Senate Minority Leader Chuck Schumer slammed what he called Stevens’ “despicable betrayal,” posting on social media that Senate Democrats were “united” in their support for El-Sayed. Other Democrats have also shared their dismay and disappointment.

House Speaker Emerita and veteran California Democrat Rep. Nancy Pelosi said on social media that Stevens “has chosen to dangerously betray Michigan families’ healthcare, freedoms and future with her horrific endorsement of Mike Rogers.”

Elissa Slotkin, Michigan’s Democratic Senator elected in 2024 and a former House colleague of Stevens from the same 2018 blue wave that saw a record number of women elected to Congress, posted on social media: “Anyone who makes an election this important about themselves, and not Michiganders and our democracy, should think hard about whether they are serving the greater good.”

Ex-Rep. Susan Wild (D, Pa.), also elected in 2018 and formerly a roommate with Stevens in Washington, said in an emotional post about the Rogers endorsement that “the fallout for Haley won’t just be in Dem politics; she will be a pariah among her friends in the Democratic caucus in Congress.”

Ex-Rep. Andy Levin, a Michigan Democrat who was elected alongside Stevens in 2018 but after redistricting lost to her in a 2022 primary, posted that Haley’s endorsement of Rogers was “unconscionable, beyond the pale.”

Stevens’ chief of staff and multiple other staffers resigned on Sunday. “I speak on behalf of our team in wholeheartedly supporting Abdul El-Sayed for Senate,” Justin German, Stevens’ former chief of staff of eight years wrote in a statement. “This election is too important to sow division or stand on the sidelines.”

Stevens’ communications director Logan Basch, appears to have also left his post: his email sent back an auto-reply to TIME that read, “Hello, as of November 1st I am no longer with the Office of Congresswoman Haley Stevens.”

The Michigan Democratic Party also appeared to have distanced from Stevens, with state party chair Curtis Hertel posting on social media Sunday: “Congresswoman Stevens is not a current member of the Michigan Democratic Party, nor will she be in the future.”

Republicans immediately jumped on the opportunity, which could offer a late boost amid an election year where retaining the majority in either chamber of Congress has looked unlikely. Rogers touted Stevens’ endorsement on social media, adding that she “showed courage and bravery in putting Michigan first” and that he’s “grateful for her support.”

House Speaker Mike Johnson told reporters Sunday as he flanked Trump upon his arrival in Iowa that he sent Stevens a note commending “how courageous she was, how much we appreciate that she’s standing for truth.”

For his part, El-Sayed, who leads Rogers in public opinion polling, has appeared unfazed by Stevens’ actions, telling reporters: “At the end of the day, I actually don’t think about Haley Stevens.” —Rebecca Schneid contributed reporting.