The laws of the United States say that Steve can scribble "warrant" on a napkin. Has this judge ruled that this ICE "administrative warrant" is any more valid than Steve's for the purposes of this case? Obviously judges, not the executive branch, are the deciders here.
The constitution (which is supreme to laws), along with common law, put restrictions on which pieces of paper that say "warrant" actually get to function as warrants, and judges, like this one, have the last word on interpreting the constitution and laws.