Keep an eye on that Second Amendment of yours. Odds on anyone wanting to try something like this would want to disarm you first.
Perhaps I should have been more explicit, but: it's my opinion (one widely shared) that one of the reasons this sort of programme hasn't taken root in the USA already is that your Constitution effectively prohibits it. In principle with the entire document, and in practice with the 2nd.
Furthermore, I think that both the 1st and 2nd Amendments act as handy mineshaft canaries. You should mistrust the motivations of anyone who seeks to abrogate either.
This is already in action to some degree in the US: employers are already able to use criminal background, public records, and (in many places) credit checks to make hiring decisions. The difference is that it's primarily private companies doing this research/scoring and some states have protections in place for prospective employees.
The 2nd amendment does nothing about these private companies using your information to limit your career options (indirectly restricting your free movement.) Anyone taking arms to protest this would rightly be considered a terrorist in the eyes of the law.
I don't really understand the political spectrum in the United States, tbh. Obviously you need to be willing to take up arms against an oppressive federal government, should such a thing happen (and who would be deluded enough to think that a military coup would be categorically impossible in any country - if not now, what about a century from now?)
You are making an unjustified leap in assuming that "liberals" are in opposition to owning firearms.
Most liberals have no real problem with people owning guns. You don't hear the vast majority of people clamoring to ban hunting rifles or shotguns.
What most people (liberal and conservative) want are sensible regulations to prevent the genuinely mentally ill or disturbed from getting guns and ammo.
The problem is that the NRA plays outrage politics in order generate funding for itself and this short circuits any useful discussion. Although, it is looking like the NRA has just been functioning as a Russian stooge for quite a while now.
As for opposing a coup? That's gonna be tough. The US is BIG. No amount of firearms in Arizona is going to help opposition in Washington DC to fight off a coup.