Rep. Haley Stevens’ supporters are pressuring Democratic leaders to back the congresswoman in Michigan’s three-way Senate primary, arguing she’s the only option for the party to avoid nominating progressive favorite Abdul El-Sayed and meeting electoral disaster.

The push to boost Stevens over state Sen. Mallory McMorrow is showing some signs of success — even if some Democrats still hold painful memories of Stevens’ stumbling start to her campaign.

“To flip the Senate, we got to go through these swing states,” Nevada Sen. Catherine Cortez Masto, a Stevens supporter, told NOTUS this week. “Moderates are more successful, and they’re usually the ones that are the ones that win.”

The pro-Stevens argument is a direct affront to McMorrow, who has used her social media savvy and promise of a new brand of Democratic politics to argue that she can unite all of the party’s factions.

McMorrow leads Stevens in some polls of the race — which more often than not show El-Sayed leading outright, and she outraised both of her opponents during the last fundraising quarter, which her campaign has said makes her the alternative to El-Sayed with the most momentum.

But Stevens’ roster of establishment backers is growing: In just the past week, she has won endorsements from Colleen Ochoa Peters, the wife of retiring Sen. Gary Peters, and former Sen. Debbie Stabenow. The timing of their endorsements wasn’t a coincidence, said one senior Democratic strategist, who described it as part of a new and broader effort to persuade previously undecided Democratic leaders to back the congresswoman’s campaign.

“There’s an appetite to move past Stevens’ stumbles in the first year of her campaign and focus on the fact that she can win now,” said the strategist, who requested anonymity to speak candidly.

The pro-Stevens effort became more urgent after El-Sayed received a raucous reception at the state party’s convention last month. The former executive director at the Detroit Health Department rode a wave of momentum this spring to consolidate support among lefty and younger voters in Michigan, vaulting him into the front-runner position, according to some recent polls of the race.

Stevens supporters say El-Sayed would lose the general election to the likely GOP Senate nominee, former Rep. Mike Rogers, in the fall. Polls of hypothetical general election matchups show El-Sayed performing worse against Rogers than either McMorrow or Stevens.

But with El-Sayed surging in recent primary polling, his campaign argues he’s the “best candidate to both energize the base and bring in voters that Dems lost in 2024.”

Democrats generally believe they must hold onto the party’s seat in Michigan to have a chance of winning a Senate majority.

“If Abdul is the nominee in Michigan, Democrats will have little hope of regaining a majority,” said Lon Johnson, a former chair of the Michigan Democratic Party and Stevens supporter. “That’s why we’re seeing senior leaders who know how to win consolidating around Stevens.”

The case for Stevens her supporters have been making to fence-sitting Democrats comes down to demographics. If El-Sayed has already won over younger and progressive voters, they say, that leaves two major blocs up for grabs for Stevens and McMorrow: Black voters and older white voters, many of whom are union members.

Those groups generally prefer Stevens to McMorrow, Stevens supporters argue, because their politics often lean more pragmatic than ideological.

“By not picking an ideological lane, Mallory McMorrow is being squeezed out by losing the progressives to Abdul, and the centrists to Haley,” Johnson said.

The Stevens campaign told NOTUS in a statement that the congresswoman is “the best, if not only, Democrat to win in November.”

The importance of the race to Democrats’ narrow hopes for Senate control have only ratcheted up tensions. Sen. Gary Peters told NOTUS that he has talked to all the Democratic primary candidates, “and all of them assure me that they’re gonna not attack each other — but I’m not naive about how it all happens.”

The reality hasn’t been so warm. Stevens was booed by party delegates as she spoke at the state party’s spring endorsement convention last month. For progressives, it was a show of strength; for party leaders, it was concerning.

Peters, who is staying neutral in the race, said he was “very disappointed” by the convention, arguing “people should treat all of our Democratic candidates with respect.”

The tone of the campaign has worried many Democrats in the state and angered some Stevens supporters, who think the congresswoman has been attacked personally in a way that crosses the line even in a competitive race. If those attacks continue, the senior Michigan strategists say, it could prompt some heretofore neutral Democrats in the state, including Peters, to make a formal endorsement in the race.

“People need to be careful what they say, even on Twitter,” the source said.

McMorrow has amassed a wealth of supporters in the party’s more liberal wing, both in Michigan and D.C. National Democrats like Sen. Elizabeth Warren, a fundraising powerhouse, and Sen. Chris Murphy have endorsed McMorrow. And McMorrow has stood out for her criticism of Senate Minority Leader Chuck Schumer, saying she would not vote for him as leader if she were elected.

“Poll after poll shows that Abdul El-Sayed cannot win a general election, and Haley Stevens is fundamentally out of step with Democratic voters,” a McMorrow spokesman told NOTUS in a statement.

Murphy said McMorrow “has the ability to appeal to everybody, and has a history of fighting and winning.”

“I don’t have anything against the other candidates, I just think that she’s our best chance to win that seat,” he told NOTUS.