Former New York City Mayor Bill de Blasio has been ordered to pay a $475,000 fine for misusing public funds during his 2020 presidential campaign, following a judge’s scathing ruling that labeled his legal challenge as “perplexing” and “entirely baseless.”

The hefty fine, initially imposed in 2023 by the city’s ethics board, stems from de Blasio’s use of an NYPD security detail for cross-country travel during his White House bid. De Blasio argued that the board provided unclear guidance on the matter and exceeded its authority in imposing the penalty.

Judge Shahabuddeen Ally dismissed these claims in an 80-page ruling issued Monday. The judge determined that de Blasio had been “expressly and specifically” advised that the city would not cover security travel costs for his campaign. Despite this, the former mayor proceeded to use the police detail, incurring significant public expenses.

“His arguments are without merit and do not withstand scrutiny,” Judge Ally wrote. The ruling blocks de Blasio’s latest attempt to avoid paying the fine and reinforces the ethics board’s authority in holding public officials accountable.

De Blasio, who served as mayor from 2014 to 2021, has faced criticism for his campaign expenditures, which some view as a misuse of taxpayer resources.

This decision marks another blow to his political legacy as the former mayor navigates the fallout from his controversial White House bid.