Washington (CNN) A federal judge has once again rebuked the administration's efforts to pressure so-called sanctuary cities, going further than any to date in using a recent Supreme Court decision to rule an existing federal law unconstitutional.

The ruling Wednesday from Judge Michael Baylson, a George W. Bush appointee, thus far applies only to his district in the Philadelphia area, but it could lay the groundwork for even more rulings that further limit what the administration can do to punish sanctuary cities -- a key priority of the administration.

The decision relies, in part, on a May ruling from the Supreme Court on state gambling laws.

federal judge in California had blocked the administration from pursuing broader funding threats. Baylson had already blocked the Justice Department from imposing new conditions on federal law enforcement grants that Philadelphia has received in the past, limiting his November ruling to the city, which had challenged the move by Attorney General Jeff Sessions. A federal judge in Chicago also has already blocked the new conditions nationwide, a ruling that was upheld in April by an appeals court . The effort from Sessions to impose the conditions had been an attempt to punish sanctuary cities after afederal judge in California had blocked the administration from pursuing broader funding threats.

But the ruling on Wednesday made Baylon's earlier preliminary decision permanent, ruling that the new conditions were illegal and unconstitutional, and went further -- declaring a seemingly obscure federal law that has served as the basis for a substantial amount of what the administration has sought to do on sanctuary cities unconstitutional itself.

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