Rep. Alexandria Ocasio-Cortez is throwing her support behind former Wayne County health director Abdul El-Sayed in the hotly contested Michigan Democratic Senate primary.

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The move, first reported by The New York Times, marks one of the progressive congresswoman’s most significant endorsements in the midterm cycle so far.

“After watching this campaign unfold for well over a year, it has become clear that Abdul El-Sayed is the strongest candidate to keep this seat in November,” Ocasio-Cortez said in a statement released by El-Sayed’s campaign. “He is building a winning coalition by putting forward an agenda that speaks directly to working people.”

El-Sayed is competing in a three-way primary, facing off against Rep. Haley Stevens and state Sen. Mallory McMorrow in the August race. The winner will advance to November’s race in one of the most closely watched battleground races. McMorrow’s campaign didn’t immediately respond to a request for comment and a spokesperson for Stevens’ campaign declined to comment.

The race is the first contested Senate primary in which Ocasio-Cortez has made an endorsement. She did not endorse candidates in contested primaries in Maine, Texas, Iowa or other states.

The endorsement comes as a waive of progressive insurgents have performed well in recent congressional primaries, and as El-Sayed, who’s framed himself as the most progressive candidate in the pivotal primary, has continued to gain steam.

“AOC has spent her career taking on the powerful on behalf of everyday people, and she has shown all of us what courageous, smart, values-driven leadership looks like,” El-Sayed said in a post thanking the congresswoman. “I’m deeply honored to earn her endorsement. Onward to victory.”

Ocasio-Cortez’s endorsement also puts her at odds with Senate Minority Leader Chuck Schumer, D-N.Y., who said he supports Stevens.

Stevens and McMorrow have previously picked up other prominent endorsements. Stevens was endorsed by The Detroit News editorial board, as well as Sens. Ruben Gallego of Arizona, Catherine Cortez Masto of Nevada and Chris Coons of Delaware, among other elected officials. McMorrow was endorsed by the Detroit Free Press editorial board, as well as Sens. Elizabeth Warren of Massachusetts, Chris Murphy of Connecticut and Martin Heinrich of New Mexico, among others.

Ocasio-Cortez’ frame of El-Sayed as the most electable candidate comes as Democrats debate what kinds of candidates have the best chance to win in November, particularly in major battleground races like Michigan, a state President Donald Trump won in 2024. Stevens’ allies believe her more moderate issue profile makes her the best candidate to bring swing voters on board this fall, while McMorrow has sought to pitch herself as a candidate who can pull from both wings of the party.

Democrats are eyeing the Michigan Senate race as a vital seat to maintain as they attempt to flip the Senate blue. Before Trump won the state in 2024, it previously went to former President Joe Biden in the 2020 election.

Sen. Gary Peters, D-Mich., is retiring, and the Democratic primary winner will likely face off against Republican former Rep. Mike Rogers. Rogers previously ran for Senate in Michigan in 2024, when he narrowly lost to Sen. Elissa Slotkin by less than 0.5 a percentage point.