The Trump administration, by way of Attorney General Jeff Sessions, announced on Monday that cities which do not comply with federal immigration law will be at risk of losing funding provided by the Justice Department for law enforcement efforts. This edict sparked strong reaction from mayors in several cities around the country, including New York, Los Angeles, and Chicago.

CBS News reports on the new policy from Justice Department:

Attorney General Jeff Sessions made a surprise appearance at the White House press briefing Monday afternoon to urge sanctuary cities to change their policies, noting that the Department of Justice plans to deny them funding if they do not begin following federal immigration laws.

“I strongly urge our nation’s states and cities ad counties to consider carefully the harm they are doing to our citizens by refusing to enforce our immigration laws, and to rethink these policies,” Sessions said.

So-called “sanctuary cities” offer safe harbor to undocumented immigrants who might otherwise be deported by federal law enforcement officials. The United States has more than 140 sanctuary jurisdictions, either cities or counties, including 37 cities. Among the sanctuary cities are San Francisco, New York, Chicago, Seattle and Los Angeles.

But the Trump administration has argued that sanctuary cities also offer safety from deportation for undocumented immigrants with criminal records.

As expected, the response from several cities was quick and defiant. New York has vowed to keep its status:

“We are going to become this administration’s worst nightmare,” said New York City Council Speaker Melissa Mark-Viverito, who was among officials gathered in New York for a small conference that attracted officials from cities including San Francisco, Seattle, Denver, Chicago, Philadelphia and New York.

Mark-Viverito and others promised to block federal immigration agents from accessing certain private areas on city property, to restrict their access to schools and school records and to offer legal services to immigrants in the country illegally.

And Mayor Rahm Emanual of Chicago, also defiant:

Mayor Rahm Emanuel doubled down on his own promise that Chicago will “continue to welcome” immigrants.

“I’ve always seen Chicago as a welcoming city,” Emanuel said in an interview from the Nasdaq stock exchange in New York on Monday.

“It welcomed my grandfather 100 years ago, we continue to welcome entrepreneurs, immigrants, and I would just say think of it this way: Half the new businesses in Chicago and the state of Illinois come from immigrants, nearly half,” he added. “Half the patents at the University of Illinois come from immigrants, and so we want to continue to welcome people, welcome their ideas, welcome their families to the city of Chicago, who want to build the American dream for their children and their grandchildren.”

And finally, Los Angeles was not to be left out:

Mayor Eric Garcetti said Monday he will fight efforts by the Trump administration to take away federal funding needed for law enforcement in Los Angeles.

Garcetti said that such actions would be unconstitutional, adding that the city’s policies are “designed to keep our residents safe.”

“Slashing funds for first-responders, for our port and airport, for counterterrorism, crime-fighting and community-building serves no one — not this city, not the federal government, not the American people,” he said. “We will fight to protect the safety and dignity of all Angelenos, and we will work closely with our representatives in Congress to make sure that Los Angeles does not go without federal resources that help protect millions of people every day.”

Among the Justice Department grants received by the city of Los Angeles in recent years include $1.8?million from the Edward Byrne Memorial Justice Assistance Grant Program, which goes to the city’s initiative for reducing criminal gang activity.

It goes without saying that this issue will eventually end up in court. Either the cities will sue the federal government for withholding funding, or the federal government will sue cities for not enforcing federal law, or a mixture of both. It’s going to be a long battle. Mayor Garcetti of Los Angeles is already using the talking points that withholding federal law enforcement funds over immigration matters will be detrimental to public safety and mean fewer police and first responders, etc… Whether that’s true or not doesn’t matter, but it makes for a good evening news sound bite in the battle of public opinion.

The amount of money in question may not be enough to make a real dent in city budgets, but any little amount matters, especially when some localities are already scrapped for cash with ballooning pension systems and crumbling infrastructure.

More from the original CBS News story on what funding is in question and how the Justice Department plans to curtail it:

Speaking in the White House Briefing Room, Sessions said the Justice Department plans to award $4.1 billion in grant money this year — but that sanctuary cities will no longer be eligible to receive them.

“The Department of Justice will require that jurisdictions seeking or applying for DOJ grants to certify compliance with [U.S. Code 1373] as a condition of receiving those awards,” he said, referring to a U.S. law which says cities cannot prevent federal authorities from enforcing immigration laws.

“The president has rightly said disregard for law must end,” Sessions said. “…Today, I am urging states and local jurisdictions to comply with these laws.”

I think the legal issues will come down to whether cities can actively obstruct federal law enforcement efforts, rather than simply say that the city isn’t responsible for enforcing federal law. For example, in New York, there were threats that the city would bar federal authorities from schools and other places if they’re looking into the legal status of a city resident. That would likely be struck down in court and the city would not be able to frustrate federal immigration enforcement efforts.

As for public opinion on the matter, it often depends on how the question is phrased, but polls do show that in general, most people feel the cities in question should comply with the law.