mikey - //It has been suggested on here that Trump could have done all this, via Congress, so I am at a loss to understand why he didn't do that ? //
I have been saying this since way before the election, and very often since -
Donald Trump has lived in a world where he transmits, and everyone receives. He is used to saying something, and it happens, no arguments, no questions, he says, people do.
I said he was going to have pretty quickly to get used to the idea that he is not in Trump Tower any more, and he will have to consult, and ask and take (!) advice, and learn that he is not autocratic anymore, and he needs to learn how politics work, because this is his world now.
And of course, he has learned nothing at all.
He uses Executive Orders because they are his comfort zone, the nearest thing he has to his old life, where he says, and people do.
Of course, he is now finding that not only do people not to what he says, but they have the law behind them - an entirely new experience for Donald, and he reacts, as he always reacts when he doesn't get his way, by baffled rage and stupid insults, belittling people and sounding petty and mean.
The reason he didn't run this by Congress, and find out in advance that it was unworkable and illegal, is because he didn't think he needed to.
Consultation, compromise, advice, being stopped - these are all brand new concepts to The President. Probably people are trying to educate him behind the scenes, but I doubt he is listening - he never had to before.