Michigan Democratic Representative Haley Stevens endorsed Republican Senate candidate Mike Rogers on Sunday, giving President Donald Trump’s party an unexpected boost in a closely watched race that could help determine control of the U.S. Senate.

Stevens, who lost the Democratic primary to Abdul El-Sayed, appeared with Rogers at a church in Detroit. “My place is not on Abdul’s campaign,” she said in a video posted on social media. Trump later invited Stevens to join the Republican Party and praised her decision.

The endorsement followed the collapse of a planned unity event with El-Sayed. Stevens had asked him to condemn an advertisement from an outside group that she said blamed Israel for high grocery prices. She told CNN that the ad was painful and suggested it could alienate Democratic voters.

El-Sayed’s campaign had recently asked Stevens not to attend its events before Election Day, saying her presence could distract from the campaign’s central issues. Rogers sought to use the dispute politically, describing Stevens’s decision as an act of courage and criticizing what he called hatred directed at a group of people.

Trump later repeated false claims describing El-Sayed as a “jihadist,” part of a broader pattern of inflammatory rhetoric from Trump and other Republicans targeting Arab Americans and Muslims.

The endorsement did not appear to weaken El-Sayed’s position in one New York Times/Siena poll released and partly conducted on Sunday. The Democrat led Rogers by 53% to 42%. El-Sayed’s campaign also said it raised $1.2 million in the four hours after Stevens endorsed Rogers, making it the campaign’s second-best fundraising day since the August Democratic primary.

El-Sayed declined to comment directly on Stevens’s endorsement, saying the race was about Michigan voters and what they need and deserve. Several members of Stevens’s congressional staff reportedly resigned over her decision, while some voters voiced anger. Pamela Johnson, a 72-year-old voter in the Detroit suburb of Warren, called Stevens a traitor after voting for El-Sayed.

Thirty-five Senate seats and all 435 House seats are being contested on Tuesday. Republicans hold narrow majorities in both chambers, while polls indicate that Democrats are favored to win the House and are in a close contest for the Senate. Michigan and Alaska are among the states expected to be decisive.

In Alaska, a federal judge on Sunday rejected a Justice Department lawsuit seeking to prevent certification of the results if Republican Senator Dan Sullivan lost by a narrow margin. The department argued that voters could be confused by the presence of a candidate named Daniel J. Sullivan Jr. on the ballot.

The issue intensified after reports that Democrat Mary Peltola’s campaign had been involved in recruiting Daniel J. Sullivan Jr. as a candidate to disrupt the race. Senator Sullivan said he would accept Tuesday’s results, despite the Trump administration’s push for a criminal investigation. Alaska Governor Mike Dunleavy, however, suggested he might not certify a Peltola victory, while Sullivan declined to say whether he would support efforts to block certification.

Sources: CNN Brasil.