While she challenged for or was in the lead in some polls earlier in the year, more recent surveys have showed her dropping back considerably as El-Sayed, running as the progressive standard-bearer, and Stevens, a more moderate candidate with support from the Democratic establishment and Senate Minority Leader Chuck Schumer, moved to the front in recent polling averages.

In late June, the Wall Street Journal cited sources saying that Peters, a close ally of Schumer’s but who had not publicly endorsed a Democratic candidate in the race to replace him, had told associates that McMorrow needed to consider leaving the race so Democrats could coalesce around Stevens to face El-Sayed, who has been criticized in the past for campaigning with an internet influencer, Hasan Piker, who critics say has made antisemitic remarks.

Then there was the outside spending, which has piled up enormously in recent weeks. Punchbowl News, a respected journalism site in Washington, wrote July 3 that a $30 million “avalanche” in ads benefitting Stevens had been booked by outside groups before McMorrow had begun to spend heavily on broadcast TV. At least one of those ads, as the Free Press reported Friday, stretched its facts in making attacks on El-Sayed.

While Stevens has called for election reform in Congress she has characterized the outside help she has received as in line with legal standards and not questioned its propriety.

But it was far from clear immediately whether McMorrow’s departure would be enough to bump El-Sayed, of Ann Arbor, out of the lead. Recent polling averages have shown McMorrow’s support in single digits and Stevens may need all of that to catch El-Sayed if those are correct.

Stevens’ level of support from staunchly pro-Israel groups, including the American-Israel Public Affairs Group (AIPAC), which also supports Republican candidates who have voted to maintain U.S. support for Israel, has also been controversial. Many Democrats have voiced skepticism of whether the U.S. should continue to give Israel the support it has given its prosecution of its war against Hamas in Gaza.

Without question, however, McMorrow’s leaving the race makes the choice a binary one for Democrats still on the fence a month before the election — which may help Stevens most since it’s presumed that El-Sayed’s supporters are already largely on board with a campaign that has been surging for months now. But predictions about El-Sayed’s levels of support topping out have been wrong before in this campaign.

El-Sayed released a statement praising McMorrow’s campaign and saying she “showed what it looks like to fight back against a politics that rigs the system against too many of us.” He then welcomed McMorrow’s supporters “to our movement to stand up against money in politics, to put money back in pockets and pass Medicare for All. We cannot allow the establishment to decide our nominee for us.”

“The same party insiders she had the courage to challenge have been bullying anyone who opposes their chosen candidate,” El-Sayed said. “After spending $30 million to drown Senator McMorrow and me out, they’re now spending even more to attack me. It’s everything we are standing up against.”

Stevens also spoke warmly about McMorrow’s effort in the campaign, though she made less of a direct pitch to McMorrow’s supporters.

“Anyone who raises their hand to serve the people of Michigan and puts forward thoughtful ideas for how they would lead earns my respect,” said Stevens, of Birmingham. “Mallory McMorrow has been an important voice, both in this race and in the state Senate, for policies that benefit Michigan’s children and families, and I look forward to working with her in the future to build a stronger Michigan for everyone.”

“As we enter the final month of the primary election, I’m excited to continue to make my case to Michiganders why I’m the strongest Democrat to defeat Mike Rogers this November, lower costs, protect manufacturing jobs, and stand up to Trump’s abuses of power,” she said.

Greg Manz, a spokesman for the state Republican Party, characterized McMorrow’s leaving the campaign as going from “a three-car pileup to a head-on collision.”

“Whoever survives the messy Democrat primary will be held accountable at the ballot box this November for turning their backs on Michigan’s working families — Mike Rogers will beat whoever emerges from their chaotic primary,” he said.

Hunter Lovell, spokesman for the Republican National Committee, said “McMorrow’s exit is the latest example of the socialist takeover. While Abdul El-Sayed and Haley Stevens tear each other apart, President Trump and Mike Rogers are delivering tax cuts and safer communities.”

Contact Todd Spangler: tspangler@freepress.com. Follow him on X @tsspangler.

This story has been updated with additional information.