Mark Levin addressed this to some extent a few weeks ago. Essentially, if an executive order bestows a person with something...its a lot harder to take it away. So it certainly won’t be as simple as revoking the executive order. The courts will become involved. Ergo, its important to fight this fully right now, before 5 million people have new ‘rights’ that can’t be taken away.
In some cases, yes.
However this EO, as onerous as it is, seems to be fairly narrow in scope. It has a defined time limit/expiration, and it only defers prosecution and deportation.
Is clearly designed as a political weapon that will land in the next President’s lap and force him to make a political decision on whether to renew it or let it expire.
If the executive amnesty is repealed, the government would probably just grandfather in all those who got amnesty. If something is arguably legal at the time you do it but is revoked or made illegal later, I don’t think you can be penalized retroactively (ex post facto).