By Tal Kopan

WASHINGTON (CNN) -- A federal judge on Tuesday blocked the Trump administration from enforcing a threat to take away funds from sanctuary cities -- the latest blow from the federal judiciary to President Donald Trump's immigration agenda.

In his ruling, Judge William H. Orrick sided with Santa Clara County, the city of San Francisco and other jurisdictions, who argued that a threat to take away federal funds from cities that do not cooperate with some federal immigration enforcement could be unconstitutional. 

In making the ruling apply nationwide, Orrick blocked the government from enforcing a key portion of Trump's January executive order on immigration, which ordered the Department of Homeland Security and Justice Department to block cities who do not cooperate with federal immigration enforcement from receiving federal funds.

While Orrick's ruling does not find the policy unconstitutional, he did find that the counties and cities that challenged the law demonstrated they could face "immediate irreparable harm" if the policy were allowed to be put into place, and that their constitutional challenge could succeed once the case is fully heard. 

The Justice Department declined to comment on the ruling and the White House did not immediately respond to a request for comment. 

He did leave the government some wiggle room, saying that his order does not block the government from enforcing conditions on federal grants nor does it block the government from creating a definition of sanctuary jurisdictions -- but the government will not be able to block federal funds from going to those cities as Trump ordered. 

Orrick wrote that the jurisdictions successfully showed they "are currently suffering irreparable harm" because the order violates rights granted to states by the Constitution and because, even if the order hasn't been carried out, it has "caused budget uncertainty" simply by threatening to take away hundreds of millions in federal funds. 

"The Counties have demonstrated that they are likely to succeed on the merits of their challenge to Section 9(a) of the Executive Order, that they will suffer irreparable harm absent an injunction, and that the balance of harms and public interest weigh in their favor," Orrick wrote. 

"This is an absolutely huge win," James Williams, counsel to Santa Clara County, told CNN. "The threat to withhold funds from state and local governments in this executive order is dead."

Order 'toothless'?

The question of what constitutes a "sanctuary jurisdiction" under the executive order, and which funds would be taken away, has been a central question for cities since it was issued. The Trump administration has made threats to punish sanctuary jurisdictions a key piece of Trump's immigration agenda.

The whole debate seemingly hinges on an obscure piece of US law. Since there is little federal law requiring jurisdictions to cooperate with federal law enforcement, the executive order only mentioned one small piece of US law, which requires jurisdictions to tell the federal government about a person's citizenship status.

While the order seemed to threaten to jeopardize all federal funds for cities the administration deemed non-cooperative, it didn't make clear what the threshold would be beyond that small law. Since the order was issued three months ago, the government has said that a definition of sanctuary jurisdictions would be forthcoming.

That uncertainty was a central focus of the arguments in the case, as well. At a hearing earlier this month, attorneys for the Justice Department offered a far narrower interpretation of the order than Trump, saying it would only apply to jurisdictions that refuse to share citizenship information as required by law, and that it would apply to only three federal grants from the Departments of Justice and Homeland Security that require compliance as a pre-condition.

Orrick was skeptical of that interpretation. 

"This interpretation renders the order toothless," Orrick wrote. "The government can already enforce these three grants by the terms of those grants and can enforce 8 U.S.C. 1373 to the extent legally possible under the terms of existing law."

The judge instead looked at Trump's own rhetoric and statements of his surrogates -- saying those contradicted the "new, narrow interpretation" that government lawyers presented in court. 

"If there was doubt about the scope of the Order, the President and Attorney General have erased it with their public comments," Orrick said. "The President has called it 'a weapon' to use against jurisdictions that disagree with his preferred policies of immigration enforcement, and his press secretary has reiterated that the President intends to ensure that 'counties and other institutions that remain sanctuary cites don't get federal government funding in compliance with the executive order.'"
   
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