A year and a half from now, Heather R. Mizeur will either be the first female governor of Maryland and the first openly gay candidate elected governor in the nation, or she’ll be growing organic herbs on the Eastern Shore. Or working on a novel. Or maybe both.

If she doesn’t prevail in her upstart run for governor, what she will not be anymore is a politician. “I’ll be done with politics,” the 40-year-old Takoma Park Democrat said. “I won’t run for elected office again.”

Last year, Mizeur, a junior member of the House of Delegates, bucked her party’s leadership by opposing the expansion of casino gambling in Maryland. Now she is the one rolling the dice, betting a promising political career on a single brash bid for the state’s top job.

Mizeur says she can win, insisting that she sees a clear path to the left of two much-higher-profile candidates for the Democratic nomination: Lt. Gov. Anthony G. Brown and Attorney General Douglas F. Gansler. She’s willing to endure the rigors of the trail and the hostility a gay candidate can expect even in a liberal bastion such as Maryland (she has already received one late-night death threat).

But if she doesn’t win, Mizeur is at ease with the prospect of walking away from the game altogether. A political junkie who has coveted elected office since junior high, Mizeur has put herself in a very public up-or-out moment.

“I’m a bit of a risk-taker, yeah,” she said, sitting next to her wife, Deborah Mizeur, at a Takoma Park cafe last week. Over orders of a poached egg on croissant with turkey bacon, they offered a frank assessment of the fork in the road ahead.

One path takes them to the executive mansion, where a Governor Mizeur would shake up what she describes as complacent state agencies and try to spark nothing less than a “transcendental shift” in Maryland civic life. Mizeur hopes her campaign — with a schedule full of playground cleanups and other hands-on community service projects — will inspire residents to think differently about their relationship with their neighbors.

“I am attempting to wake people up to the notion that we are not disconnected individuals,” Mizeur said. “We live in a community.”

But should she lose, she has no interest in returning to the District 20 seat she has held in the House of Delegates for two terms. It is a job she characterized as both rewarding and maddening.

“It is the best job I’ve ever had, but I’m also experiencing frustration about the larger issues that need to be addressed,” she said. “I cannot be agitated by these injustices and not move to try to address them, and I’m not able to address them as a delegate.”

She dismisses a run for federal office, saying Washington is too dysfunctional. Nor is she interested in a Cabinet post in Annapolis, where she “would be hemmed in by somebody’s else’s politics.”

Better, Mizeur said, would be a more private life in the couple’s Craftsman-style house near downtown Takoma Park and at their farm near Chestertown, on the Eastern Shore. She could try her hand at writing or perhaps start a nonprofit group to take on gender, racial and economic injustices. She might work on oyster restoration in the Chesapeake Bay.

“I have a lot of interests outside of politics,” Mizeur said, leaning briefly into Deborah’s shoulder. “I have a beautiful life.”

“The truth is,” said Deborah, a former health-policy expert on Capitol Hill and now a clinical herbalist, “whether Heather is an elected official or unelected, she will always be engaged in her community because that’s where her heart is.”

‘Weird things can happen’

The conventional wisdom in Annapolis is that Mizeur has little chance of winning. Gansler, who hasn’t officially launched a campaign, had $5.2 million in the bank as of January. Brown has steadily racked up endorsements from Maryland Democrats in the race’s opening weeks and claims to be closing the funding gap with Gansler.

Mizeur, meanwhile, has never run for statewide office and served only a single term on the Takoma Park City Council before running for the District 20 delegate’s seat in 2006. None of her State House colleagues have officially endorsed her, including the seven other openly gay members she worked closely with last year to pass the same-sex marriage initiative.

Lawmakers say they are staying neutral for now. Off the record, there is plenty of grumbling about a second-term delegate rushing to the front of the queue for higher office. Mizeur waves that off as the carping of party insiders who are overly protective of their own careers.

“I reject the idea of next-in-line politics,” Mizeur said. “Campaigns should be about ideas.” And maybe about gender.

“Historically,” she said, “62 percent of Maryland’s primary vote comes from women.”

With the primary just under a year away, most handicappers rank Mizeur as a likely third-place finisher. Brown, who would be Maryland’s first African American governor, is considered likely to do well among black voters in Baltimore and his native Prince George’s County. Mizeur will have to compete with Gansler on their home turf of Montgomery County.

“I hate to think of any candidate as a spoiler. But without question, her being in the race is going to make it harder for Gansler to win,” said Todd Eberly, a political science professor at St. Mary’s College of Maryland. “But primaries are very strange animals, particularly in Maryland. When you’ve got low turnout in a three-person race, a lot of weird things can happen.”

Mizeur, who put more than 20,000 miles on her Chevy Volt traveling the state as she considered a run, started a buzz in April when she came in second to Brown in a small straw poll of Democrats in Western Maryland. Observers began to note the strengths that make her campaign something more than a vanity effort, including the potential to attract money from national gay and women’s groups, a network of connections from her nine years on the Democratic National Committee, a rousing campaign style and a reputation for strategic thinking.

“I think only a political fool would underestimate her candidacy,” said Keith Haller, a Bethesda-based pollster-analyst. “To some degree, she’ll be a national story as a gay candidate seizing on the same-sex marriage issue, which is arguably one of the hottest issues in the country.”

A political childhood

Mizeur grew up in rural Illinois, where her grandparents were farmers and her father was a union welder at a Caterpillar plant. The family lived on $45-a-week strike pay for six months in the 1980s.

She was brainy, studious and fascinated with politics. She remembers taking notes on the Ronald Reagan-Jimmy Carter presidential debates when she was 7, and she produced a Mizeur voting guide for her extended family each election for years. She told her family she was gay in 1993, when she was attending the University of Illinois at Urbana-Champaign.

It was a shock, at first. “Think about how different it was then,” she said. “Things felt rocky for a couple of weeks. And then it very quickly faded off, and they came to see me as the person I always was.”

She came to Washington as a policy wonk, working on heath care for various congressional Democrats and advocacy groups. She advised then-Sen. John F. Kerry (Mass.) on heath-care issues during his 2004 presidential campaign. Indeed, her relationship with Deborah, a one-time aide on the U.S. House Ways and Means Committee, is a love founded on heath-care policy.

“I remember the first time we met,” Deborah said. “It was in 1999 in the Hart Building at a . . .

“No, no,” Mizeur interrupted. “I remember because I was so smitten with you. It was in the Capitol, in one of those side offices.”

They married in 2005 in a ceremony along the Chesapeake Bay, with Mizeur’s parents in attendance. In 2008, in California, they held a second ceremony in a Napa Valley courthouse to get a proper marriage license. “It really caught us off guard, how emotional it was to have a government agency recognize our marriage,” Mizeur said.

The couple bought a house a few blocks outside the ward Mizeur had represented for one term on the Takoma Park City Council. She had already announced her intention to run for the state legislature and resigned her council seat a few months before the end of her term, which still rankles some in town.

“I’ve heard from some progressives here who are hugely enthusiastic about her candidacy” for governor, said Keith Berner, a Takoma Park activist and author of the Left-Hand View blog. “I’ve also heard from people who feel like Takoma Park was only a stepping stool for her.”

To have a chance, Mizeur has to be the liberal candidate in a state just coming off a run of splashy liberal victories, from wind-farm subsidies and benefits for undocumented immigrants to gun control and the repeal of the death penalty. As a delegate, she introduced the Kids First Act, which allows agencies to use income-tax forms to identify uninsured children eligible for subsidized health care. She pushed for expanded family planning for low-income women and delighted environmentalists with her early opposition to natural gas fracking.

But in Maryland, the liberal track can be crowded. Brown, for his part, was a champion of ending capital punishment, and Gansler, as attorney general, decreed in 2010 that the state would recognize same-sex marriages performed elsewhere.

“It’s exciting that all three candidates want to run as progressives,” said state Sen. Jamie B. Raskin (D-Montgomery), “and that all three can lay claim to progressive victories we’ve seen in the last three years.”

The week after announcing, Mizeur was still refining her stump style in northeastern Baltimore. After reading Shel Silverstein poems to fourth-graders at the Goodnow Community Center, she stumbled slightly when referring “to my . . . my spouse.” But a few minutes later, in a room full of middle-schoolers, she hit the issue head on.

“When I got into politics, I was told, ‘You can’t run for office, you’re a girl,’ ” Mizeur said. “I’ve also been told that I couldn’t be in office because I’m gay.”

Many of the students looked shocked; several heads snapped up, and two girls at a back table locked eyes with surprised expressions. But Mizeur pushed on, speaking louder, looking at each student in turn and imploring them to have faith in their personalities. And soon, they we were answering back, church style. “Uh-huh.” “Yes, yes.”

“We are all perfect just as we are,” Mizuer said, before wrapping up to loud applause.

“That was surprising, yes,” said Ryan Trafton, 21, a Goodnow counselor. “I wasn’t sure how the kids would react to that, but she really brought them along. I could see her as governor.”