how any of this is legal. The constitution

The problem is that you respect and believe in words. The people currently in charge could give two fucks. Ultimately, words only have the power that we give them, so when those in charge ignore the Constitution, then the Contitution has no power.

I have severe ADHD. It's funny in a way because when I was younger, I tried to understand the rules of my employers and follow them. And yet I still lost jobs. In part because of issues related to ADHD specifically, but in part because what companies SAY the rules are is not what the rules are. If you've worked in a corporate environment, you know that there's go-to people for things. And while there's official processes (or maybe even not), what ACTUALLY happens is that someone goes to the person who can do something and asks them to do it, and generally they do, and that's like 75% of how business actually runs.

In the same way, there are rules and decorum and traditions in politics and revolve around the Constution and various bodies of legislature, et cetera. And so there's nothing that ACTUALLY forces anyone to follow any of that except voluntary compliance or physical threat because policing bodies enforce things.

This is why the rich are free, largely, from most crimes. They aren't enforced. And this is how our democracy crumbled. The Constitution hasn't been repealed. It doesn't have to be. It is simply ignored. Worse, those who claim to follow it shit on it and ignore it and throw it out.

The constitution prohibits “ex post facto” laws - how can you revoke someone’s documentation when they complied with the laws as they were at the time?

I agree with you generally that this should be illegal, but it probably isn't.

It definitely isn't ex post facto; this is not a law that punishes anyone from a legal perspective, it merely changes the requirements for a certain privilege (the ability to drive a vehicle). If it declared these licenses invalid before the date of the law (which could carry punishments for illegally operating vehicles), then it would be ex post facto.

Another way to put it is that it simply makes a certain action illegal which was previously legal, and laws do that sort of thing all the time. Consider that in the US you didn't need a driver's license in order to drive at all until 1913. The NJ law requiring drivers licenses also "revoked" someone's privilege even though they complied with the laws previously, requiring them to get a permit from then on. But, since it didn't introduce any punishments for not having the permit before it was introduced, it wasn't ex post facto.

Of course the law is also clearly discriminatory, but US's extremely limited anti-discrimination laws are likely not broad enough to be applied here.

The current events should awaken many people to the sad fact that US laws and its entire legal system exists primarily to protect the wealthy and the powerful from everyone else; all other functions are secondary. As such, many horrible, immoral, and unjust things are legal under US laws, and many others will be twisted into being legal by the supreme court.

I'm currently outside the US but I'm pulling my hair out trying to renew my passport. I don't even care what's on it. The Nazi bastards don't give a fuck, the cruelty is the point

I've been trying to revive my childhood passport from my birth country since I fully expect passports to be next

I don't understand how any of this is legal

That's the thing - It's not. They don't give a shit, and the judicial system isn't doing anything about it