No president has asserted a blanket power to reject any request that doesn’t suit him, until Donald Trump. No president has rejected requests made by Congress on the grounds that the committee requesting is controlled by Democrats, until Donald Trump. If Congress refuses to appropriate funds for a border wall, build it anyway.
If the Administrative Procedure Act requires a notice-and-comment procedure before changing regulations, skip the procedure and announce it anyway. If a racist sheriff gets caught harassing Latinos, pardon him. Urge police to beat suspects, urge crowds to shoot immigrants. If a federal trial court rules against a Trump business, attack the judge as “Mexican”. If a federal judge rules against the “travel ban,” attack the “so-called judge.” If a Court of Appeals agrees about the travel ban, threaten to abolish it. If another judge halts the asylum rules, call him an “Obama judge.” If the chief justice mildly protests that the judiciary is independent, tell him he’s wrong.
Without norms, the Constitution is powerless. There are no norms with Trump. Everything he does is abnormal. Donald Trump is a walking, breathing Constitutional crisis.