Coronavirus spreads. But don't panic! (topical thread)

[Alan V]

"President Donald Trump said late Monday night he will sign an executive order temporarily suspending
immigration to the United States as the nation battles the health and economic effects of the coronavirus
pandemic. 'In light of the attack from the Invisible Enemy, as well as the need to protect the jobs of our
GREAT American Citizens, I will be signing an Executive Order to temporarily suspend immigration into
the United States!' he tweeted."

I also note that legislative statutes and regulations promulgated by government agencies,
presidential executive orders are "subject to judicial review and may be overturned".

Could someone please clarify this?   

Trump has no legal training, but impulsively tells people to do things he may or may not have the authority to compel, regardless.  People are always scrambling to clarify the boundaries in the separation of powers which he presses against.  It's a repeated problem with his brand of aggressive ignorance.