A microcosm of a bigger fight, Democrats vie for progressive mantle in Michigan governor's race Three Michigan Democratic hopefuls are vying for the progressive label.

Ahead of the state’s Aug. 7 primary, Democrats in Michigan are fighting a pitched battle that is symbolic of the one raging within the party in races across the country this midterm cycle: which candidate best embodies the modern progressivism that is making its way into the mainstream of Democratic politics?

Come November, it is likely to be one of the most competitive gubernatorial races this cycle.

Michigan’s incumbent governor, Republican Rick Snyder, is term-limited, presenting Democrats with an open seat pick-up opportunity in a state that Donald Trump won by just 0.3 percent in the 2016 presidential election, his slimmest margin of victory statewide in any contest.

The opportunity has Democrats eager to see who will emerge victorious from the primary crop, which has narrowed to three main contenders: former state Sen. Gretchen Whitmer, former Detroit Health Department director Abdul El-Sayed and businessman Shri Thanedar.

All three have sparred on the bread-and-butter issues of healthcare, education, taxes and the all-important topic of infrastructure –- a constant frustration of Michigan voters.

But beyond the policy squabbles, they have been waging a fierce fight to claim the mantle of progressivism that has found renewed strength following the victory of Democratic Socialist Alexandria Ocasio-Cortez last month, who unseated a Queens, New York party boss and a potential speaker of the house candidate in Congressman Joe Crowley.

On Wednesday, El-Sayed gained a major endorsement from Sen. Bernie Sanders, who praised the 33-year-old for his embrace of a progressive policy platform.

"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 released by El-Sayed's campaign.

The state of Michigan holds particular importance for the Vermont senator, who scored an upset victory in the 2016 Democratic primary over Hillary Clinton that injected new energy into his presidential bid.

Ocasio-Cortez, fresh off a campaign swing throughout the Midwest with Sanders last week, will head to Michigan this weekend to aid El-Sayed, who would be the nation's first Muslim governor if elected in November, as the race enters its final days.

“Alexandria Ocasio-Cortez proved to us that an authentic message of what government can do to support poor and working people against the dominance of corporations can move our politics,” El-Sayed said of the 28-year-old Ocasio-Cortez’s visit.

Whitmer, the former minority leader of the Michigan State Senate, has racked up an impressive slew of local endorsements from elected officials, powerful unions and progressive groups like Planned Parenthood and the Sierra Club says her governing experience makes her the most progressive choice in the race.

“As Senate Democratic Leader, I negotiated to expand Medicaid to more than 680,000 Michiganders. I negotiated a minimum wage increase... I even shared my story of surviving sexual assault when women’s health was on the line,” Whitmer told ABC News, “I’m proud to have the support of almost every major labor union and progressive group in the state...They endorsed me because they know I’m a strong progressive who can actually get things done.”

El-Sayed has voiced support for the abolishment of the U.S. Immigration and Customs Enforcement agency (ICE), marijuana legalization and has embraced a single-payer health care system for Michigan, a central policy plank the modern progressive movement.

Thanedar, a self-funding, eccentric millionaire, and chemist with a compelling personal background, says his background and policy positions, like support for a single-payer health care system and a plan to raise taxes on the ultra-rich to funding the state's public education system, make him the most deserving of the progressive label.

“My ultimate goal is single-payer health care...I want to eliminate the influence of dark money, Thanedar told ABC News in an interview at his Ann Arbor campaign headquarters in April.

“But more than that I have lived a progressive life...I struggled, I slept in my car and when it got too hot I slept in the chemistry building at the university where I was teaching,” said Thanedar.

“I’ve never given an employee less than $15 an hour. So it’s fine for someone who comes from privilege and go make speeches about $15 an hour and about poverty and about income inequality,” an implicit swipe at El-Sayed, who he says is not qualified to be the state’s governor.

Thanedar also said Whitmer was unqualified for the job, and says the accomplishments she refers to in the state legislature, like Medicaid expansion, were the result of the willingness of a Republican governor to compromise with Democrats.

“Snyder broke from the rest of the Republican governors and took advantage of Obamacare’s money to expand Medicaid. And she takes credit for that,” Thanedar said, “I think about a person that has worked for 15, 14 years in politics, term-limited in the House, term-limited in the Senate cannot name a few accomplishments, and had to borrow accomplishments from others.”

The health care debate has been front and center in the race, and at a recent debate in Detroit, the tensions between the candidates continued to boil over.

El-Sayed dinged Whitmer, the daughter of a former Blue Cross Blue Shield executive, over a fundraising effort Blue Cross led on her behalf, and what he claims is her close relationship with insurance companies, saying she is “taking money from those same corporations, those same individuals, who want to maintain the status quo,” when it comes to healthcare.

Whitmer has not indicated support for a single-payer healthcare plan like El-Sayed and Thanedar, but instead refers again to her work in the state legislature as evidence she will push for “quality, affordable health care” for Michiganders, according to her campaign.

“She’s the only candidate in the race who has actually expanded coverage for Michiganders,” campaign spokesman Zack Pohl recently told the Associated Press.

A nationwide April poll from the Washington Post and the Kaiser Family Foundation found that 51 percent of Americans and 74 percent of Democrats support having a single-payer health care option where they would receive insurance from a single government plan.

Thanedar, who has faced questions about his progressive credentials given his past donations to Republican presidential candidates like John McCain, name-checked Sanders in voicing his support for “Medicare for All” health care system.

“I support Bernie Sanders’ Medicare For All, the expanded plan, at the national level – if we can that, that’s great; if not, I’ll do it at the state level,” Thanedar said.

Of his past donations to Republicans like McCain, Thanedar defends himself by citing his more generous donations to Democrats.

"They make a big deal about me giving $2,300 to John McCain, I've given $29,000 to Democrats, and there's only one Republican I gave money to," Thanedar told ABC News.

In less than two weeks, after the political jostling subsides and voters from both parties choose candidates, the nominee will face a matchup with either the state Attorney General Bill Schuette, who was the backing of President Trump, or Michigan Lieutenant Governor Brian Calley, who has Snyder’s support after serving alongside him for eight years.

The last Democrat to capture the governor’s mansion in Michigan was Jennifer Granholm, who won re-election in 2006 over Republican Dick DeVos, the husband of current U.S. Secretary of Education Betsy DeVos.

ABC News' Lee Harris contributed to this story.