Syracuse mayor Stephanie Miner could be a formidable foe in the 2018 governor’s race. Michael J. Okoniewski for City of Syracuse

Andrew Cuomo, pragmatist progressive extraordinaire, wouldn’t seem at first glance to be someone who would be vulnerable to a primary challenge. He was the governor who passed same-sex marriage into law years before the Supreme Court legalized it. In certain parts of the state, the minimum wage will soon be $15 an hour. Public college tuition, with many caveats, will soon be free.

Yet a competition is already underway to mount a primary challenge to Cuomo, a Democrat who has alienated plenty of liberals as he slogs toward a third term. Cynthia Nixon, the Sex and the City star and a progressive activist in her own right, is openly contemplating whether to run. Brooklyn Councilmember Jumaane Williams, known for his work on criminal justice reform, is mulling a bid. A former state senator from the Hudson Valley, Terry Gipson, is campaigning across the state.

The fourth candidate, Stephanie Miner, differs from her potential competition in two crucial ways: She has executive experience, and she has a history of working with, and then defying, Cuomo.

“For me, being a progressive means having values you believe in,” Miner, the mayor of Syracuse, tells the Voice. “You act consistently with those values, regardless if they’re popular at the time or not popular.” Cuomo, she says, “has been forced by public action and, frankly, by fear of backlash to do the kinds of things he’s done.”

Miner is wrapping up her second and final term as mayor of Syracuse, the state’s fifth largest city. She has been a rumored Democratic candidate for a congressional seat held by Republican John Katko, but the buzz of late has been around her gubernatorial ambitions.

Miner is one of the few Democrats anywhere to consistently challenge Cuomo on policy. In 2013, she attacked Cuomo in a Times op-ed for failing to help financially stressed towns and cities with sufficient state aid and relief from their ballooning pension obligations. She has been a critic of Cuomo’s use of tax subsidies to lure business to the state and chided him for not investing nearly enough in aging infrastructure. She scuttled a plan to build a sports arena in Syracuse, opposing the Republican county executive — a top ally to the GOP-friendly Cuomo.

Before all that, it looked like Cuomo viewed Miner as a part of his political future. In 2012, he appointed her co-chair of the New York State Democratic Party, which has functioned as little more than a campaign piggybank for Cuomo. Two years later, Miner resigned her post after publicly clashing with Cuomo over his policies.

Miner says she was inspired to run after speaking in March in front of a group of teachers who belonged to the statewide teachers union, which bitterly clashed with Cuomo — a supporter of charter schools — during his first term. “I got a standing ovation for the speech and after the standing ovation, a number of teachers stood up and asked me in this crowded room if I would run for governor,” she recalls. She also told the Daily News in July that the day the Voice published a story urging Democrats to challenge Cuomo, she received 35 emails, with the story attached, from people asking her to run.

In addition to charters, Miner has taken Cuomo to task for underfunding poorer school districts and pushing policies that “scapegoat teachers.” Were NYSUT, the state teachers union, to spurn Cuomo and spend heavily on Miner, her candidacy could be formidable. (They were neutral in 2014.)

She is a harsh critic of Cuomo’s enabling of the Independent Democratic Conference, a group of eight senate Democrats, including one from Syracuse, who are in a long-term power-sharing alliance with the Republican conference. Cuomo has been something of an IDC patron, encouraging its formation and rarely challenging the group publicly.

“The governor can’t have it both ways,” says Miner. “He can’t say he’s got all these accomplishments because he’s a progressive leader and at the same time he’s actively or passively, depending on the time of year, what day you’re talking about, supporting the IDC’s existence.”

For Democratic voters weary of a governor swinging from the poles of fiscal conservatism to big liberal government, Miner offers a clear alternative: She proudly supports investments in mass transit and has vowed never to tamper with CUNY’s funding, as Cuomo threatened to do. There would be no needless, deeply personal fights with the mayor of New York. She has promised to fully comply with the Campaign for Fiscal Equity lawsuit, which found the state to be chronically underfunding low-income school districts.

For Cuomo, governing in the mold of a Clintonian centrist — with bursts to the left on college tuition, paid family leave, and the aforementioned minimum wage — has not been a good look, especially in the age of Trump. Not helping matters is the upcoming corruption trial of a former top aide, Joe Percoco, who was so close to Cuomo he was regarded as a surrogate brother.

Cuomo’s job approval numbers until recently have been on the decline, though his favorability rating among Democrats still hovers at 69 percent, according to an August Siena College poll. What may give Cuomo allies pause, however, is the name Zephyr Teachout — and how the political climate has shifted to the left since she ran against Cuomo three years ago.

Miner, who would be New York’s first female governor, hopes to build on the performance of Teachout, who was an unknown law professor with few campaign resources when she challenged Cuomo and garnered 34 percent of the vote, much of it from outside New York City. The upstate counties that threw their support to Teachout and, later on, Bernie Sanders in the presidential primary would all be places where Miner, or any Cuomo challenger, could draw serious support.

The challenge will be raising enough money to compete statewide and building name recognition. Miner is unknown in New York City, which provided 52 percent of the votes in the 2014 primary, according to Jerry Skurnik of Prime New York. If the major labor unions of the state quickly close ranks around Cuomo, it will make Miner’s life much more difficult.

The key to actually toppling Cuomo in a primary will be cutting into his support from nonwhite voters in Brooklyn and Queens. White progressives in the brownstone belt and Manhattan already don’t like the governor, and could be easily swayed by Miner or anyone else who takes the plunge.

Cuomo, though, won 65 percent of the vote in Brooklyn, 72 percent in Queens, and 77 percent in the Bronx against Teachout, who couldn’t afford TV ads in the city’s expensive market.

As of now, it appears unlikely that more than one prominent Democrat will challenge Cuomo. Most are expected to drop away if progressives settle on a single candidate, or the Working Families Party — permanently estranged from Cuomo — deems one contender most viable.

Miner said she is in no rush to declare her candidacy, and wouldn’t say when she thought she would have to decide one way or the other. She’s likely waiting to see how much support from donors and various progressives she can garner to make her campaign viable.

“For the first time in my life, thinking about running for office, I don’t feel like I have any clock ticking. As a nontraditional candidate, one of the benefits I have is I can do it on my own timeline.”