Over a decade ago, the immigrant-rights movement seized the national spotlight with a risky act of civil disobedience: It turned May Day 2006 into A Day Without Immigrants, an unprecedented day of strikes and protests in more than 50 cities to prove immigrants’ vital role in the economy, and to demand comprehensive immigration reform. Now, facing a president who threatens to launch even more oppressive border regime, immigrants are once again taking industrial action one workplace at a time—this time, a little bolder, a little angrier, and a little more confident that their communities have their back.

On Friday at Northeastern University in Boston, dining service workers with UNITE HERE Local 26, which represents workers at area universities and hotels, staged a one-day strike to defend “Our American Principles.” They rallied behind set of moral guidelines that Trump seems determined to violate from day one, but which the union sees as non-negotiable for both the labor and immigrant rights movement: “our commitment to diversity and equality for all…respect for one another’s race, ethnicity, gender, religion and sexual orientation” and the precept that “wherever we were born or however we came to America, we all belong here.”

Even in a relatively liberal city like Boston, Local 26 felt compelled to stage a preemptive strike as an opening salvo in the coming battle against Trumpism on the local level. And city lawmakers also recognize their plight: Boston has for several years upheld “sanctuary policies,” an informal category demarcating a line of non-cooperation between federal authorities and police on immigration-law enforcement. Since 2014, under legislation known as the Trust Act, Boston police have generally refrained from aiding federal enforcement (though federal agents can generally intervene for specific investigations, with an explicit warrant).

Sanctuary policies have enabled nearly 50 cities nationwide, according to Politico, to avoid, to varying degrees, actively collaborating on a federal immigration crackdown (for instance, by rejecting Homeland Security’s “hold” requests for police to detain immigrants on the agency’s behalf, pending federal detention). For workers, these protections provide some reassurance that they can go to work each day or complain to authorities about an abusive boss without having to worry about a cop demanding to see their ID.

Since the election, Boston has reaffirmed its defiance, despite Trump and many conservative lawmakers’ threats to slash federal funding for sanctuary cities. Last November, Councillor Josh Zakim clarified that Boston would continue “providing sanctuary from the type of immoral and illegal federal overreach that President-elect Trump has promised throughout his tawdry campaign.”

In another sanctuary city, Minneapolis, a major hub for migrants in the heartland, Mayor Betsy Hodges reaffirmed that giving in to the administration’s pressure would be riskier for her community than continuing its protective policies: “Witnesses and victims of crimes won’t come forward if they think our police officers will question or detain them about their immigration status.”

While the sanctuary policy limits the policing of immigrant communities, it may also have a knock-on effect of helping immigrants defend workplace rights. Sanctuary policies are designed in part to make workers feel empowered when they’re on the right side of the law, and one major labor group, Centro de Trabajadores Unidos en la Lucha (CTUL), demonstrated this after the election by staging a defiant strike for contracted retail janitorial workers.

CTUL represents workers who, according to their surveys, earn on average a starvation wage of less than $15,000, and also suffer widespread anti-immigrant discrimination, including bosses threatening to retaliate by “calling police and immigration agencies on workers.”

For seven years, CTUL has worked with SEIU to unionize hundreds of janitors at several chain retailers, including Target, Whole Foods, and Best Buy. Janitors again rallied for workplace justice at Home Depot on Inauguration Day, carrying a banner at a Home Depot in Northeast Minneapolis that declared, “On Strike Against Trump and Poverty Wages.” In a statement decrying the contracting arrangement as the “Trump Model of Business,” CTUL organizer and grandfather Luciano Balbuena stated, “We cannot get ahead with how the economy is currently structured…. What kind of future awaits our children and grandchildren if we don’t fight back now?”

The answer is coming back loud and clear to Washington. Post-election, with the White House gearing up for wall building and mass deportations, some cities have moved toward more open defiance by formalizing their sanctuary policies, including Santa Ana, California, and Burlington, Vermont.

Back in Boston, Local 26 wants employers to go further by instituting sanctuary-type policies for workplaces by committing to “keeping ICE out unless they have a warrant.” They call on both government and employers to reject other regressive measures Trump and anti-immigrant lawmakers have floated, including the revival of so-called “Muslim registries” used to surveil immigrant communities.

As the strike stretched through the early evening, dining-services worker Heidy Barreiro felt confident marching alongside other local protesters, as crowds of workers and activists swelled in solidarity. “We made the decision to go on strike today to make everyone feel the way we feel—that we don’t support this administration,” she says, “that we are going to fight back.”

Barreiro, who has worked at Northeastern for six years, under the Obama administration, is preparing with her community for a new political era—and now Boston’s more than 650,000 immigrant residents face the added challenge of fighting simply to be recognized as fellow workers and fellow Americans. Though people were initially frightened, she recalled, “after today, after we’ve gone on strike and shown people that workers do have power, that we’re going to stay strong, that we’re gonna continue to fight, things feel different. Things feel more clear.”

Whether immigrants seek to hold crooked contractors accountable, or want the freedom to push for decent jobs and organize unions without risking arrest, local legal protections and workplace empowerment go hand in hand. Now with Trump threatening to bring a reign of lawlessness to American cities, the most precarious workers are redefining public security: The issue may not come up in contract talks, but a safe, fair workplace regardless of immigration status is key to social inclusion, promoting economic fairness, and helping communities exercise the rights they do have—especially those without a say in who gets elected to office.