Just what powers do a court actually have against an entity like the IRS. If the IRS just says go to hell and flat refuses to cooperate, what can a judge do with his own army? Can a President break an IRS stonewall? They are all Civil Service over there and it would take an actual Act of Congress to change anything and even that couldn’t accomplish much without an army of marshal if the IRS bosses are determined to not submit.
If Trump can get DOJ cooperation, he could have the judge issue a search warrant. Then FBI agents could just walk in, demand records, and immediately cuff anybody who gives them crap.