RaAnah Killebrew, 23, is already paying off debt. Not from college, or buying a car, or too many fancy electronics. Just the basics — back rent and utility bills.

Working two minimum wage jobs in Pittsburgh, at McDonald’s and Dunkin’ Donuts, she had to drop out of culinary school and move in with an aunt.

“I could always go back to school, but my bills are not just going to wait for me to get around to paying them,” says Killebrew, who now works as a cashier and keeps shelves neat at Big Lots, earning $7.75 an hour. She’s only working about 20 hours a week now, though she’d like to work more, and relies on food stamps to make up the difference.

“I can’t maintain that on anything less than $15. That’s just the facts. There are so many factors that come with making the money you need to make.”

On Thursday, Killebrew will take that conviction to the streets, skipping her shift to join low-wage workers in protests across the country — organizers said they would occur in 190 cities — under the slogan “$15 and a union.” She’s participated in similar actions before, while she was still working at McDonald’s; the labor-backed campaign has been mounting periodic strikes at fast-food restaurants for two years now. But this is the first time retail workers have joined the effort, outside of a series of strikes against Wal-Mart, which has long been a favorite target of labor unions, sometimes to the exclusion of other low-wage retailers.

The protests began last night, with workers shutting down gas stations in Kansas City and Detroit. The Pittsburgh actions will start at a local McDonald’s, Killebrew says, and move to a few “undisclosed locations.”

“The fact of the matter is, it’s not just fast food where you’re being treated a certain way,” Killebrew says. “It’s retail, it’s security, it’s hospitals, it’s everywhere, where you’re not making the money you need to make to maintain.”

The $15 an hour campaign, which began with a few hundred workers at walking off their shifts at a handful of restaurants in New York  two years ago, has metastasized. Home health-care aides joined protests in September. Federal contract workers took up the cry last month.

Airport workers at 10 major hubs are expected to join in Thursday’s protests. Workers at discount and convenience stores started showing up to meetings over the past few months too, and with employees in 22 cities signed up to participate — at BP, Shell, Speedway, Family Dollar, Dollar Tree, Dollar General, Marathon, Sunoco and more — nearly every truly low-wage job in America is represented.

All of it has been backed by the Service Employees International Union, which already has active organizing campaigns in a few of those sectors — airports and home health aides — and would gladly take on the rest. To do so, the union has sought to align itself with the burgeoning number of hourly workers left behind by a minimum wage that has failed to keep up with the cost of living, and a growing recognition that the proceeds of their labor are flowing disproportionately to the top of the income ladder.

“The economy — and our country — are out of balance because so many people are trying to raise families on service-sector paychecks but are getting crushed as corporations use their power to push down the wage floor,” said SEIU president Mary Kay Henry, in a statement on the eve of the protests. “The Fight for $15 movement is growing as more Americans living on the brink decide to stick together to fight for better pay and an economy that works for all of us, not just the wealthy few.”

Gas stations and discount retail chains are a logical extension of those who have joined the “Fight for 15” so far. The sector is large and growing. Gas stations and their convenience stores — many owned by oil companies, which represent one of the most profitable industries in America — employ more than 750,000 workers, who make $10.71 an hour on average, working only about 31 hours a week.

Dollar stores and discounters like Big Lots boomed through the recession, as customers without much to spare gravitated there from superstores like Wal-Mart. Discount goods mean discount wages, with most employees making near the minimum. Big Lots Senior Vice President of Human Resources Mike Schlonsky declined to comment on the protests, other than to say the company “takes great pride in providing industry competitive compensation to all of our associates and offering benefits to those who are eligible.”

The Chamber of Commerce has brushed off the strikes: “Small business franchise owners and their employees shouldn’t be subjected to the intimidation tactics of the SEIU and its squads of paid protesters,” said the Chamber-backed Workforce Freedom Initiative in a statement. “While dressed up as worker rights protests, these PR stunts are really about securing new dues payers for the SEIU.”

SEIU denies that anyone is paid to attend the protests, although striking workers do get a small amount — less than a day’s wages — from SEIU’s strike fund. But at least two things the Chamber says are true: The campaign is more about public relations than actual economic coercion, since the most direct outcome has been to shift the conversation around minimum wages such that $15 no longer sounds outlandishly high, and some local jurisdictions have even moved to make it a reality. And those who participate do in fact seem interested in joining a union.

Killebrew, for example, thinks it would be useful in backing employees up when management itself isn’t following its own rule book. Employees get punished arbitrarily, she says, and nobody’s there to defend them.

“Before I learned about this whole movement, I wasn’t really aware of how many rights that we actually have, because a lot of places aren’t telling people,” she says.

The Fight for 15 staff have made it clear to interested workers that participating in the protests is safe.

“A job cannot fire you because you went on strike,” Killebrew says. “We have lawyers for that, who make it known to them, these are your rights.”