Supporters of a proposed ballot measure to increase the District’s minimum wage to $15-per-hour rally Wednesday at the John A. Wilson Building. (Aaron C. Davis/The Washington Post)

A coalition of labor and social justice groups launched a ballot campaign Wednesday to raise the minimum wage to $15 an hour in the nation’s capital, an effort that could place the District at the center of a growing national debate over income inequality.

The announcement coincided with protests by thousands nationwide for higher wages. Choosing tax day as their backdrop, workers walked off minimum-wage jobs in fast-food restaurants and retail stores to draw attention to a two-year-old rallying cry for a more livable hourly wage.

If successful, the D.C. measure would set the minimum wage at more than twice the federal rate — and put the District alongside Seattle and San Francisco in a liberal vanguard on the issue. On Wednesday, supporters pointed to new polling, an expected heavy turnout in a presidential election year and the backing of the financier of last year’s successful measure to legalize marijuana in the city as evidence that the campaign should be taken seriously.

But in forcing the issue in 2016 — and in a place with the symbolic importance of Washington — supporters also risked drawing intense opposition from business interests, as well as thrusting Democratic politicians into a no-win choice between unions and employers.

The measure could also tee up another showdown between the District and a GOP-controlled Congress. Although some bipartisan support exists on Capitol Hill for raising the minimum wage, a $15-per-hour rate would be viewed by many conservatives as an affront to the federal minimum wage of $7.25. As they tried this year with the marijuana legalization effort, lawmakers could use their vast oversight powers of the federal district to block the ballot measure from taking effect.

Raising America’s lowest wages

None of those concerns came up Wednesday, when supporters announced the campaign before a cheering crowd of more than 200 on the steps of the District’s John A. Wilson Building on Pennsylvania Avenue NW.

“This fight is not about what Wal-Mart would say it’s about, it’s not about profit shares, it’s not about stock prices and it’s not about bottom lines,” said Delvone Michael, director of D.C. Working Families, a leading organizer. “This fight is about real people. This fight is about who we are as a city and what we become as a nation.”

With the federal minimum wage unchanged in six years, 29 states have raised hourly wages above the federal rate; 15 of those have additional increases scheduled in the coming year and a handful of mostly West Coast cities have gone much further.

Last year, Seattle and San Francisco became the first major U.S. cities to pledge to phase in a $15-an-hour wage by the end of the decade. The District, New York City and other East Coast cities have imposed a living wage on city contractors, but none of them have seriously weighed $15 an hour for the private sector.

The D.C. measure would mirror Seattle in phasing in a flat $15-per-hour minimum wage by 2019. That would be 30 percent higher than the $11.50 rate that the D.C. Council and mayor backed last year.

The ballot measure would also for the first time force D.C. restaurants to pay workers a minimum wage plus tips, as in San Francisco. Restaurants in the District are required to pay only $2.77 per hour, as long as tips bring servers up to the equivalent of minimum wage or higher.

“We’re talking about righting a historic wrong,” said Meg Fosque, national policy director for the New York-based Restaurant Opportunities Centers United, or ROC, which has joined the D.C. coalition. Fosque said that with 7 in 10 wait staff employees being women and many being of color, the D.C. measure would force candidates and voters to confront the stark issues of income inequality and a gender pay gap.

Workers in retail, fast food and other industries protested across the nation on Wednesday, calling for the minimum wage to be raised to $15. (The Washington Post)

Michael Czin, spokesman for D.C. Mayor Muriel E. Bowser (D), declined to say whether the mayor would endorse the ballot campaign.

“As with any grass-roots advocacy effort, we look forward to hearing directly from residents about issues important to them,” he said.

The city’s restaurant association and Wal-Mart, which recently opened its first stores in the District, did not return calls or e-mails seeking comment.

Harry Wingo, president of the D.C. Chamber of Commerce, said Wednesday that businesses were alarmed by the proposal.

“A dramatic wage hike could have a measurable impact on how easy it is to do business in the city,” he said. Wingo noted that the council just approved a three-step increase in the minimum wage last year. That ramp up includes a dollar increase to $10.50 this summer, and another, to $11.50, next summer.

“We’re already on track to increase it dramatically. That would be the highest in the region,” he said.

Thorn Pozen, a D.C. lawyer who specializes in city election law, said advocates will first face the hurdle of getting the measure on the ballot. City law prohibits ­citizen-sponsored ballot measures that could adversely impact the District’s budget. The Board of Elections has broadly interpreted that regulation in the past to block measures.

But advocates will have someone on their side who succeeded with an initiative last year to legalize marijuana, which also arguably cost the city money.

Adam Eidinger, who led the signature-gathering drive on Initiative 71, said he is confident the coalition will get its signatures and qualify for the ballot. Eidinger said that to raise awareness of the issue, he would go on a pot strike next year, refraining from using marijuana until D.C. voters pass the measure.

“I want to do something more than just marijuana,” he said, “and this is incredibly important.”

Eidinger’s deep-pocketed boss is also on board.

David Bronner, the head of hemp-infused Dr. Bronner’s Magic Soaps, met with leaders of the coalition last month. In a recent interview with The Washington Post, Bronner said he would start with a financial investment of $200,000, more than he spent to underwrite the city’s marijuana initiative.

“This whole economic recovery has completely left wages behind. We’re talking about hiking the minimum wage. This isn’t a living wage,” Bronner said. “Let’s just say that when Wal-Mart has a holiday food drive for their own employees, come on.”

The final plan was based in part on polling the coalition conducted last month that suggested that backers would start with at least 70 percent approval among likely D.C. voters.

“I think it’s so popular because middle-class folks are feeling squeezed, too. Everyone understands this is an issue,” said Michael, of D.C. Working Families.

Lisa Brown, executive vice president of 1199SEIU, which represents home health-care workers, mobilized dozens to attend Wednesday’s announcement. She said her group would work to make sure voters realize how pervasive low-wage jobs are in the District.

“The sad condition of America is that most of these people are not kids, not teenagers. These are grown people, and in our case, ones who take care of some of the neediest people in our society, making minimum wage,” Brown said. “People don’t like to speak about a class warfare, but there is a class warfare. . . . We have to stand up now.”

Abigail Hauslohner contributed to this report.