BOSTON — An Obama-appointed judge in San Francisco just delivered a massive win for sanctuary cities, slapping down President Trump’s bid to cut off billions in federal funding.

U.S. District Judge William Orrick III, nominated by Barack Obama in 2013, ruled late Friday that the White House cannot strip cash from Boston, Chicago, Los Angeles, Denver and dozens of other cities because they refuse to play ball with ICE.

The decision shields billions of dollars from Trump’s immigration crackdown and keeps sanctuary jurisdictions flush with federal money — at least for now.

The Obama connection

Orrick is no stranger to controversy. Before his lifetime appointment, he reportedly raised more than $200,000 for Obama’s campaign and donated over $30,000 to groups backing him.

In 2015, Orrick also issued a restraining order against activists who released undercover videos targeting Planned Parenthood — a move that made him a hero to progressives and a villain to conservatives.

Now, that same judge is standing between Trump and his effort to force cities to cooperate with immigration enforcement.

Billions on the line

Trump’s executive orders directed Attorney General Pam Bondi and Homeland Security Secretary Kristi Noem to yank federal dollars from any city that limited ICE cooperation. Another order demanded agencies across Washington withhold payments that might “abet sanctuary policies.”

But Orrick said Trump can’t govern by threat, ruling that the President has no authority to unilaterally pull the plug on federal funding streams.

For cities like Boston, which have resisted ICE detainer requests, the ruling means billions are safe — a stinging rebuke to Trump’s campaign promise to punish sanctuary jurisdictions.

Trump’s crackdown stalls

The Department of Homeland Security had even published a list of more than 500 “noncompliant” jurisdictions, only to yank it down after critics noted it bizarrely included Trump-friendly counties.

Trump’s Justice Department has sued New York, Los Angeles and others, but Friday’s ruling underscores a growing pattern — the courts keep stopping him.

Sanctuary cities celebrate, Trump fumbles

Boston, Chicago and Los Angeles declared victory almost immediately. The White House, caught flat-footed, offered no response Friday night.

For Trump — who once promised to cut off sanctuary city funds “so fast your head will spin” — the San Francisco courtroom handed down a reality check.

And critics say the fact that an Obama mega-fundraiser turned judge is the one keeping Boston and LA’s federal billions intact is just salt in the wound.