Almost immediately after President-elect Donald Trump claimed victory, blue-state governors pledged to protect their migrant populations from what Trump has promised will be the largest mass deportation operation in American history, The Latin Times reports.

Cities like Los Angeles, Chicago and Philadelphia were among the first to pledge to protect their local migrant communities from the Trump administration’s initiative. Even as the president-elect claims that cities have no choice but to deport people living in the country illegally, some of these cities and states have begun passing laws to prevent mass deportations targeting their migrant communities. Here’s a closer look at their efforts:

Los Angeles, California

California Governor Gavin Newsom announced shortly after the election that he had called a special legislative session focused on “Trump-proofing the state” and safeguarding progressive policies.

The Los Angeles Unified School District has declared itself a sanctuary for migrants and the LGBTQ+ community, adopting resolutions that reaffirm schools as safe havens from immigration enforcement and bar staff from voluntarily sharing the immigration status of students and their families with federal agents.

Chicago, Illinois

Chicago Mayor Brandon Johnson said the city “will not bow down” to tough immigration policies. “Chicago will remain a sanctuary city despite Donald Trump’s threats,” the mayor said at a press conference.

Johnson said he is prepared to fight any effort to block federal funds from flowing to Chicago because city officials will not cooperate with mass deportation efforts and will work to prevent immigration agents from arriving. Johnson described the threats as “unconscionable and dangerous,” calling the president-elect a “tyrant” in the same interview.

Philadelphia, Pennsylvania

Philadelphia remains a sanctuary city, a status it has had since 2016 that prohibits collaboration between the Philadelphia Police Department and U.S. Immigration and Customs Enforcement (ICE). Pennsylvania Gov. Josh Shapiro, however, stopped short of expanding the measure to the entire state, referring to a statement focused on unity after Trump’s victory.

“Now that his election is over, it’s time to govern — to work together, to compromise and to get things done,” Shapiro said in a statement after the election results. “I believe there is more that unites us than divides us — and we must work together to continue to get things done for Pennsylvania.”

Boston, Massachusetts

Mayor Michelle Wu told WCVB-TV that she will protect immigrants without legal status in “every way possible.” Similarly, Massachusetts Gov. Maura Healy said on MSNBC that she would use “every tool in the toolbox” to “protect our residents” and “hold the line of democracy and the rule of law.”

Healey, who as the state’s attorney general during Trump’s first term repeatedly challenged his administration on immigration policies, also said she would exercise her executive and regulatory authority and use state law to fight several Trump policies.

Denver, Colorado

Denver Mayor Mike Johnston said he would use Denver police to stop federal forces from deporting migrants in an interview. Denver police also said state regulations prevent them from enforcing immigration law, but did not confirm whether they would actively block Trump’s policies, Axios reports.

Two days later, Johnston softened his stance in the 9News interview, but insisted that his administration and local residents would resist such deportations, saying he was “not afraid” to go to jail to stop Trump’s efforts.

Tom Homan, who was named by Trump as the new “border czar,” also said that the new administration plans to withhold federal funds from states and localities that refuse to cooperate with its mass deportation efforts. In an interview, he suggested he would have no problem putting Mayor Johnston in jail if he decided to follow through on his position.

Colorado is already in the spotlight in the immigration debate, with Trump and his ilk making exaggerated claims about Venezuelan gang activity in Aurora, where Trump has promised to begin his deportations.

The pushback from Democratic-led states and cities in the face of Donald Trump’s mass deportation promises reflects a commitment to protecting immigrant communities. As local leaders move to implement policies that ensure the safety and support of migrants, it is clear that the immigration debate will continue to be a polarizing issue in the United States.