Rep. Alexandria Ocasio-Cortez, D-N.Y., endorsed progressive candidate Dr. Abdul El-Sayed on Wednesday in Michigan's Democratic primary for U.S. Senate.

El-Sayed, an epidemiologist, is in a three-way race to vie for an open seat in a top battleground state.

Sen. Gary Peters, a Democrat, is retiring. Former Rep. Mike Rogers is the presumptive Republican nominee, while El-Sayed is being challenged by Rep. Hayley Stevens and state Sen. Mallory McMorrow, who both lean more toward the center.

Senate Minority Leader Chuck Schumer, D-N.Y., has endorsed Stevens in the Aug. 4 contest.

"Despite our ideological differences and whatever disagreements there are in the party, every single one of us sees this moment as existential," Ocasio-Cortez told The New York Times. "And I think many people are willing to put aside differences in order to give us the best chance at winning. And I think that Abdul gives us that right now."

Progressive Democrats recently won congressional primaries in New York City and Colorado, though Ocasio-Cortez did not endorse a candidate in those races.

If elected, El-Sayed, who supports progressive proposals such as Medicare for all, would be the nation's first Muslim senator. He has been leading in recent private and public polling, the Times reported.

Ocasio-Cortez told the Times she was impressed with El-Sayed's online messaging skills.

"Just like it's extremely challenging to run candidates that can't raise money, it's also just as challenging to run a candidate that can't message online," Ocasio-Cortez said.

"I think we've now kind of crossed this Rubicon where online and digital messaging is no longer a niche. It is a core competency, just like any other," Ocasio-Cortez said.

El-Sayed said he was thrilled to receive the Queens lawmaker's endorsement. He also received an endorsement from the United Auto Workers union.

"I'm honored for what her support says about what this campaign is building and what we're fighting for," El-Sayed told the Times.

Ocasio-Cortez previously endorsed El-Sayed during his 2018 campaign for Michigan governor.