Wouldn't be illegal to them until a court today says it is. Even then, as you know, Trump people would either appeal or ignore a decision against them. You know what the law means to them. Can only hope, as you, that Dems and others are working as quickly and carefully as they can to minimize the damage Trump is doing.
I'd guess, Trump's wrecking ball actions, including his effort to usurp Congress's constitutional right to be master of the nation's "spending purse" would not be seen as 'giving comfort to the enemy' in Trump's Supreme court. Although Putin and Xi would be applauding about every domestic move Trump is making.
The likely position of SCOTUS on any and all questions of illegality would have to be a major consideration of the opposition to Trump, I'd guess.
It was Plato who said, “He, O men, is the wisest, who like Socrates, knows that his wisdom is in truth worth nothing”