An early test of a Mamdani-Trump relationship? Security clearance.

“It would be very difficult for the mayor of New York City to not have a security clearance,” said John Sandweg, a former acting general counsel at the Department of Homeland Security, which approves clearances to local officials. “Denying it would be unusual and more impactful than any of the other revocations that the administration has done.”

Trump has used federal security clearances as a tool for retribution against his political enemies, yanking them from elected officials including New York State Attorney General Letitia James and Manhattan District Attorney Alvin Bragg. The president has expressed alarm at Mamdani’s rise and, before the Nov. 4 election, threatened to pull funding from the city and send in the National Guard should Mamdani succeed in his bid for Gracie Mansion.

The president has not mused about denying Mamdani’s clearance. And security experts like Sandweg said doing so would be highly unorthodox and denote a major escalation on behalf of the White House, given the level of information sharing between the NYPD and federal law enforcement, and the city’s ongoing status as a potential terror target.

While Trump has yanked the clearance from the likes of former President Barack Obama and Hillary Clinton, former government officials are unlikely to be proactively read in on high-level security threats, which are typically discussed on a need-to-know basis, making the revocation more of a symbolic gesture, Sandweg said.

The mayor-elect and the president have had sharp words for each other. During his fiery victory night speech, Mamdani called out Trump directly, telling the president to turn the volume up if he was watching the address on television (the president appeared to have tuned in.)

Trump, in turn, has lobbed all manner of threats at Mamdani. In July, he amplified questions about Mamdani’s citizenship and threatened to arrest the 34-year-old if he were to interfere with federal immigration enforcement in New York City. Mamdani was born in Uganda, came to the United States when he was seven and became a U.S. citizen in 2018. A GOP Congress member, Tennessee Rep. Andy Ogles, has even called for the mayor-elect to be deported.

When asked about granting Mamdani a security clearance, the White House press team directed POLITICO to a recent briefing in which Press Secretary Karoline Leavitt was asked about Mamdani’s intention to touch base with the president — though she deferred to Trump.

A spokesperson for DHS said the department does not discuss security clearances. Mamdani’s team declined to comment.

Federal law enforcement officials typically look at things like criminal history and whether someone could be compromised financially — if they had significant debt, for example — when approving clearances. The fact that Mamdani was elected mayor, whose responsibilities include making decisions like shutting down infrastructure in the event of a major public safety breach, Sandweg said, would factor heavily into that accounting.

“Even if somebody had concerns, he is still the duly-elected mayor, and you want to honor the selection by the citizens of New York,” he said.

Mayors are not automatically entitled to a clearance. When the current mayor, Eric Adams, faced a five-count bribery case, experts told POLITICO that federal law enforcement likely reexamined his credentials knowing that other high-ranking officials in the NYPD had access to top secret information and could help Adams make decisions without filling him in on the particulars.

Mamdani, however, has no obvious triggers for denial, according to Terence Monahan, who served as the NYPD’s chief of department under the de Blasio administration.

“There’s nothing he has done and nothing in his history the FBI or Homeland Security could point to and say he can’t get it,” Monahan said. “It would be infantile if they didn’t give it to him.”