NEW YORK — Last week, on the kind of fall day in Brooklyn that movies are made of, U.S. Labor Secretary Thomas Perez stepped onto a modern union shop floor — in this case a children’s playground — for a lesson in community organizing.

“If I don’t have a child with me, I introduce myself as a domestic worker,” says Allison Julien, a nanny who also represents the National Domestic Workers Alliance, a nonprofit aimed at improving working conditions for caregivers. The park is one of the few public places where nannies gather in public, where organizers can approach them. But many of the immigrant women are still skittish.

“Lots of undocumented workers want to be invisible,” explains Jennifer Bernard, another nanny-organizer, as kids whiz around on scooters underfoot. “They’re not going to talk to us if they’re in the presence of their employers.”

Perez watches quietly, introducing himself only as Tom, as staffers and Secret Service agents linger on the perimeter. He asks questions: What’s the most important quality in an organizer? (“Patience,” they answer.) When you meet someone, how do you gain their trust? (“Smile.”)

One woman beckons them over, pinned to her bench with a baby and its accoutrements, to ask what the small party is up to. When Julien and Bernard tell her, she describes an argument she was having with her employer, involving a missed text message and harsh words. “I said, 'You don’t talk to me like that,' ” the nanny on the bench said.

The organizers applauded her courage and asked for her phone number. Maybe she’ll come to a meeting sometime soon. “We’re all over, any time you need us!” Bernard said.

But later, meeting with Perez back in the basement of the Carroll Gardens Library, the organizers let their cheery veneer down. When the labor secretary asked what still frustrated them, they told him domestic workers still lacked protections under the law — and the enforcement to follow up.

“The situation seems the same,” Bernard says. "What are we really doing? Because it sickens me when we hear so many of these stories now.”

Even on a day touring New York to showcase workers who had found ways to regain some semblance of bargaining power — from carwasheros to the recently unionized staff of Gawker — Perez is intensely conscious of the reality that change is slow. He’s got a wish list of new laws that would make the modern workplace more friendly for working families: Mandatory paid leave. A higher minimum wage. Meaningful penalties when employers violate the law.

But Republican and business opposition to those priorities has rendered them fantastical on the federal level, leaving Perez scrambling to shore up workers rights with the regulatory equivalents of duct tape and string. The reality wasn’t lost on Gawker union organizer Hamilton Nolan, who was invited to attend the White House’s Summit on Worker Voice last week.

"This summit at the White House,” Nolan wrote, "was an implicit acknowledgement that the Obama administration does not currently possess the requisite political power to pass the sort of meaningful progressive legislation that might actually start to change some of the dynamics that we were all there to decry.”

Nonetheless, Perez has another list of things he’s done to make the most of his time in office. “I’m not waiting for a functional Congress to do my job,” he said in the back of an SUV, crawling through Brooklyn traffic to get to his lunch with car wash workers. “And the good news is, I have ample tools in my toolbox to do my job.”

Take home health aides, who care for elderly people and the disabled. Two years ago, the Labor Department issued a rule requiring most employers to pay them minimum wage and overtime, which previously had not been required as a result of an exemption. Implementation was delayed by a lawsuit from private home-care agencies, who appealed it all the way up to the Supreme Court, which handed Perez a victory this month by declining to take the case.

Or take the rule for deciding who should be entitled to overtime generally, which the department is in the process of updating. Progressives have hailed the possible change as one of the most important things the Obama administration could do to keep employers from saddling workers with more hours for no extra pay, but the proposals being discussed get workers only back to where they were in the 1970s and still faces intense Republican opposition in Congress.

The Obama administration has checked some workers rights items off its wish list by executive order, mandating paid leave, pay equity and a minimum wage hike — but only for workers on federal contracts. For the rest of the population, Perez has made some headway by aggressively policing underpayment and misclassification of jobs in low-wage industries.

"Laws and regulations are only as good as the political will of the people who enforce them,” Perez says. “We have a whole set of laws on wage theft, and you look at what happened in the previous administration and you look at what’s happened here.”

What the administration can’t accomplish by fiat, or through Congress, Perez has been encouraging states and cities to pursue on their own. He’s sprinkled a few million dollars across several cities to help them design paid leave laws, spent time on the phone with mayors helping them navigate local opposition, and traveled across the country championing those who succeed. The department even embedded a staffer in Seattle to help it build an enforcement unit as the city implemented one of the nation’s first $15-an-hour minimum wage laws.

“I have grown to appreciate the catalytic force that the bully pulpit can be, that the technical assistance can be, that our grant making can be,” Perez says.

Ultimately, though, it’s just nibbling on the edges of the problem. State and local governments can’t do anything about America’s troubled immigration system, for example, which keeps undocumented workers too afraid to demand better treatment on the job — and which Perez, whose parents were born in the Dominican Republic, takes very personally.

“What is it about the amazingly courageous and productive people in that room that threatens folks?” Perez wonders, after leaving the meeting with nanny-organizers. "They’re building communities, they’re organizing communities, they’re doing some of the most important work in our communities, but there are some people banging the drum of anti-immigrant sentiment.”

So even after defending his department’s accomplishments to a polite but challenging audience at Gawker, Perez had to admit that none of it was earth-shaking. By the last stop on his tour of freshly organized workplaces, his voice was scratchy, but he still held forth with the energy of someone running for office — until the end, when a tinge of fatigue crept into his patter.

“Everything is a workaround, just about,” Perez told the young, mostly white staffers, arrayed on the steps of a steep auditorium in their sleek lower Manhattan offices.

Still, Perez hasn’t lost sight of the factor that might ultimately give some future labor secretary a more friendly environment: politics. He talks about the number of Latino people who are eligible but not registered to vote yet, for example, and the need to redraw congressional districts to avoid creating ideologically driven electorates. He can’t do much about it while in office, but he knows people with money who can.

“I’ve sat down with philanthropy and talked about that, the need to organize, organize, organize,” Perez says. "You might not get a return on investment next year, but you’ve got to invest in it, you’ve got to be in it for the long haul, because that’s the key to success."

In the meantime, through whatever power of leadership his position conveys, Perez is trying to water the seeds of organizations that might help workers stand up and fight for themselves. Sometimes it’s something as symbolic as traveling to Detroit, meeting with fast food workers who’ve been active in the Fight for $15. “The Fight for $15 is more than a number,” he likes to say. “This is a movement for fairness and voice.”

While staging photo ops with worker organizers, Perez has also met in private with the people at whom the Fight for $15 is aimed — the CEOs of fast food companies, who like to emphasize the franchisees who worked their way up from the behind the grill to own their own businesses. Perez says he respects their initiative but thinks focusing on the opportunity for enrichment through entrepreneurship is missing the point.

“These stories are remarkable — but because of the failure to pay their workers a decent wage, these stories will never be told,” Perez says. “That really works to your disadvantage, because you have a chronic image problem. That’s a self-inflicted wound.”

The question, for Perez, is how to help scale those new worker organizations without the protective laws that first allowed the labor movement to flourish. “For every National Domestic Workers Alliance, there are far too many communities who don’t have Jennifer to speak for them,” he says, of the nanny organizers.

Right now, the labor secretary is just trying to make sure people know that options for collective action still exist — despite the lack of legal aids to help them out.