Fresh off a Kansas tour with Alexandria Ocasio-Cortez, Sen. Bernie Sanders (I-Vt.) is endorsing one of the left’s last high-profile challengers of the year — Abdul El-Sayed, a candidate for governor of Michigan in the Aug. 7 primary.

“Under Abdul’s leadership, Michigan can help lead the nation in guaranteeing health care for all through a Medicare for All single-payer type system; tuition-free public colleges and universities; a minimum wage of $15 per hour; and strong environmental protections,” Sanders said in a statement.

El-Sayed, 33, launched his campaign early in 2017 after leaving the Detroit Health Department, which he reestablished after budget cuts had shut it down. He enjoyed early attention from national media outlets, which were intrigued by his age, his Muslim faith — there has never been a Muslim governor of any state — and a Sanders-style platform in one of the largest states Sanders won in the 2016 presidential primaries.

Momentum didn’t immediately follow the media spotlight. El-Sayed spent weeks fighting to prove his Michigan residency because he had relocated to New York for work before moving back to the state. Gretchen Whitmer, a former state Senate leader who would be the state’s second female governor, locked up endorsements from labor unions and Democratic legislators. Shri Thanedar, a wealthy chemical testing executive, self-funded a series of ads that sold him as the race’s true “progressive” candidate. For a few weeks, he led El-Sayed and Whitmer in the polls.

But El-Sayed, whose campaign is led by veterans of Sanders’s 2016 bid, positioned himself as the next breakout star of this year’s Democratic primaries. His campaign organized a “People’s Summer” program, modeled on the 2016 Sanders operation, to out-organize Whitmer with volunteers. This weekend, El-Sayed will campaign in four Michigan cities alongside Ocasio-Cortez, the upset winner of a Democratic House primary in New York; before his primary, he will campaign with Sanders.

“We’ve been super excited about the energy around this campaign, and Sen. Sanders took note,” El-Sayed said in an interview. “He saw what we’re building, organically, on the path that he put together in 2016. I’m very thankful to have his endorsement; he’s the progressive leader in the United States.”

Ocasio-Cortez, whose victory over longtime representative Joseph Crowley surprised reporters and pollsters, has personally raised the profile of El-Sayed and other left-wing challengers. El-Sayed and Thanedar have both attacked Whitmer for opposing single-payer health care and asked whether her donations from Blue Cross Blue Shield were the reason; Thanedar has even run a TV ad invoking the 2016 campaign, portraying Whitmer as the candidate voters are being “told” to support by their leaders.

Michigan’s sparse polling has nonetheless found Whitmer comfortably ahead of the field, with two polls this summer showing her with around 40 percent support as El-Sayed and Thanedar poll in the teens. They have also found Whitmer running ahead of the two Republican front-runners, while El-Sayed runs behind.

Michigan, however, looms large for Sanders and his supporters as a place where pollsters have been repeatedly embarrassed. Polls found Hillary Clinton leading Sanders by double digits ahead of the March 2016 primary, and the Detroit Free Press briefly, inaccurately, called the race for her on election night. In November 2016, an average of Michigan polls gave Clinton a four-point lead; she lost the state by less than half of one percentage point.

“Polling in Michigan is notoriously bad,” El-Sayed said. “If I win this primary, this becomes one of the most important races in the country, and folks all over Michigan will be paying attention.”