A man so unfettered, so used to getting his way, is unlikely to concede that, as president, he might decree anything that could be challenged by an agency as meddlesome as a court of his peers.
Mr Trump has not always been so dismissive of the refuge America’s courts offer.
One estimate suggests he has initiated around 3,500 actions over issues as diverse as tax, property deals, battles with disgruntled casino customers, or myriad personal defamation lawsuits.
This extraordinary appetite for confrontation is unlikely to diminish now that he sits in the most powerful office in the world.
The ruling is a reassurance that America’s institutions are not cowed by the stridency of Mr Trump’s governance.
They have not allowed themselves be sidelined by blowhard diktats unsupported by constitutional legitimacy.
That Republican efforts to silence senator Elizabeth Warren backfired so spectacularly also suggest Mr Trump may not have the free hand he and his supporters imagined they would once they reached the White House.
Mr Trump seems determined to test the limits of legality to achieve his aims.
Maybe he should read one of the biographies on the rise and fall of one of his predecessors, Richard Nixon.