There is no exact definition of a constitutional crisis. Presumably it’s when the United States Constitution is in crisis. And it is in crisis now, today, because the president of the United States is abusing it to entrench his power.
As long as he can get away with it, as long as Republicans who control Congress won’t stand up to him, as long as Americans who oppose this have no capacity to stop him, even though they may be in the majority, this rogue president will do more and more damage to our system of government. And the constitutional crisis will worsen.
A malignant megalomaniac facing no countervailing power will continue to expand his terrain until he is stopped.