The rule takes effect September 18. It allows federal immigration officers to deny green cards to applicants determined likely to become dependent on government welfare. New York City Mayor Zohran Mamdani filed suit to stop it before the ink was dry.

His argument, delivered with the subtlety of a fire alarm: "People will die."

Mamdani — the democratic socialist running America's largest city — announced the lawsuit from a podium flanked by supporters, claiming the Trump administration's public charge rule is an "undisguised effort to strip New Yorkers of the services they rely on." He projected that "up to four million people could unenroll from their health care alone, including 1.8 million children," and estimated a 10.6 percent increase in premature mortality rates in New York City's immigrant communities within five years.

Those numbers deserve a second look. The rule applies to prospective green card applicants — people who have not yet received permanent residency. It does not strip benefits from U.S. citizens. It does not revoke existing green cards. It asks a straightforward question that American immigration law has asked since the 1880s: can you support yourself, or are you planning to live off the taxpayer?

The coalition Mamdani assembled tells you everything about what's actually being defended here. Chicago, San Francisco, Seattle, Santa Clara County, and King County filed alongside New York City in U.S. District Court for the Southern District of New York. Separately, New York Attorney General Letitia James launched her own challenge with 21 states and the District of Columbia. James said the policy "preys on fear" and that her office previously defeated a similar rule and would do so again.

The Trump team's response was to mock the entire effort. And why wouldn't they? The lawsuit's core demand is that the federal government be prohibited from considering whether a green card applicant intends to collect Medicaid, SNAP food assistance, housing aid, or CHIP benefits. Strip away the legal language and the press conference theatrics, and the coalition is asking a federal judge to guarantee that immigrating to America for the purpose of going on welfare remains a protected path to permanent residency.

The Biden administration had quietly loosened enforcement of the public charge standard, declining to weigh most benefit usage in green card decisions. USCIS issued new guidance in August restoring the tougher standard. The September 18 effective date simply returns the policy to where it was before Biden's team decided self-sufficiency was an unreasonable expectation for people seeking to live here permanently.

Mamdani called the rule "cruelty." That framing requires you to accept that asking immigrants to support themselves is cruel, while asking American taxpayers to fund benefits for people who haven't arrived yet is compassion. Twenty-one state attorneys general apparently find that framework compelling enough to take to court.

The public charge doctrine is not a Trump invention. It is not a Republican invention. It predates the income tax, Social Security, and the New Deal. For more than a century, the baseline expectation for permanent residency in the United States was that you would not become a ward of the state. The only thing novel about the current rule is that someone had to reinstate it after the previous administration pretended it didn't exist.

So now we have a democratic socialist mayor, a state attorney general with a losing record on immigration cases, and a coalition of the most expensive cities in America — cities already buckling under the cost of services for their existing populations — suing for the right to import more people who will need those same services.

The rule takes effect Friday. The lawsuit asks a judge to stop it. The Trump administration's position is that American immigration policy should favor people who can take care of themselves. The coalition's position is that this expectation is illegal.

One of those positions has to be explained at a press conference. The other one explains itself.