California’s “sanctuary city” mayors are vowing to resist President Donald Trump’s effort to make them obey immigration laws, after he signed an executive order Wednesday cutting off federal funds to “jurisdictions that willfully refuse to comply.”

Sanctuary cities and states are those that have offered shelter to illegal aliens by refusing to cooperate with federal officials in enforcing of federal immigration laws — in some cases, even refusing to turn over criminals for deportation proceedings.

President Trump promised on the campaign trail to end sanctuary cities, and Wednesday’s executive order is the first step in carrying out that pledge. It declares: “Sanctuary jurisdictions across the United States willfully violate Federal law in an attempt to shield aliens from removal from the United States. These jurisdictions have caused immeasurable harm to the American people and to the very fabric of our Republic.” The order stipulates that such jurisdictions “… are not eligible to receive Federal grants, except as deemed necessary for law enforcement purposes by the Attorney General or the Secretary [of Homeland Security].”

That has California’s sanctuary city mayors in a state of panic — and open rebellion against the new Trump administration.

In San Francisco, where Kate Steinle was infamously murdered in broad daylight in July 2015 by an illegal alien and felon with multiple convictions and deportations, Mayor Ed Lee told a press conference on Wednesday: “I am here today to say we are still a sanctuary city.” He added, according to the San Francisco Chronicle, “We stand by our sanctuary city because we want everybody to feel safe and utilize the services they deserve, including education and health care. … It is my obligation to keep our city united, keep it strong … crime doesn’t know documentation. Disease doesn’t know documentation.”

Oakland’s Mayor Libby Schaaf echoed Lee, warning that Trump’s order would “destroy trust in government” and complaining that “it’s disrespecting the American tradition of a peaceful transfer of power,” the San Jose Mercury News reported.

Los Angeles mayor Eric Garcetti was quoted by Southern California Public Radio’s KPCC as vowing to resist “coercion” by the Trump administration. He also said in a statement:

The idea that we do not cooperate with the federal government is simply at odds with the facts. We regularly cooperate with immigration authorities — particularly in cases that involve serious crimes — and always comply with constitutional detainer requests. What we don’t do is ask local police officers to enforce federal immigration laws — and that’s an official LAPD policy that has been enforced for nearly 40 years. That is for everyone’s good, because trust between police and the people they serve is absolutely essential to effective law enforcement.

Garcetti also speculated that President Trump would not actually cut off federal funds to the city if it defied his order: “It would be folly for any administration to take away funds to protect America’s port. … Or take away vouchers that help get veterans who have fought for our country off the street,” he said, according to the Los Angeles Times.

San Jose Mayor Sam Liccardo, who managed to blame Trump when leftists led a violent riot against Trump supporters last June as local police stood idly by, joined the chorus of defiance. “We are not going to engage in immigration enforcement, and we are also not going to engage in conspiracies with immigration officers that are going to undermine our ability to maintain the trust and relationship that we currently enjoy with our entire community,” he said on Wednesday, according to the Mercury News.

California’s newly-installed attorney general, Xavier Becerra, was similarly defiant, declaring in one of his first press statements: “Executive orders do not change existing law. Executive orders cannot contradict existing law. And Executive orders can be challenged for violating constitutional and legal standards in their enforcement. … The California DOJ will protect the rights of all of its people from unwarranted intrusion from any source, including the federal government.”

Sanctuary city mayors and state officials appear to be pinning their hopes on the constitutional principle that the federal government cannot compel or commandeer state and local governments to carry out its functions.

However, they will struggle to find an answer for their own arguments from just a few years ago that immigration law is an area of exclusive federal jurisdiction that supersedes state and local law. Democrats made that case passionately against Arizona’s SB 1070, which allowed local law enforcement officers to ask people whom they stopped for another legitimate purpose to prove that they were legally resident in the United States. (The law was largely struck down at the Supreme Court.)

Furthermore, there is nothing states and municipalities can do about the power of the federal government over its own funds.

One city in California agreed with Trump’s policy: Fresno, the state’s fifth-largest city and the heart of the conservative Central Valley. The city’s new mayor, Lee Brand, told the editorial board of the Fresno Bee: “I’m not going to make Fresno a sanctuary city because I don’t want to make Fresno ineligible from receiving potentially millions of dollars in infrastructure and other types of projects … My philosophy is to follow the law and to avoid these national culture-war questions.”

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named one of the “most influential” people in news media in 2016. His new book, How Trump Won: The Inside Story of a Revolution, is available from Regnery. Follow him on Twitter at @joelpollak.