While a pan-US national awareness is widely seen as emerging during the civil war the rest of what you are saying is disingenuous. Prior to that it was a selection of colonies etc. which very much had borders because skirmishes over taxation rights was a thing.

There was significantly more inter ethnic strife in the US pre WW2 than most people seem to appreciate, much of it relating to if encountered (by whatever means) people should be settled/assimilated/rejected. There were riots/protests of this type in major cities at least between the civil war and the 1930s, and state policy reflected this, such as with the Chinese exclusion act which would hardly have been possible without a border.

The problem is the old man and his enablers have zero respect for the law, whereas the other team does (they are not above reproach but in this regard they are distinctly different).

This makes the fight unfair, as without law all we have is unbridled violence as a tool and that is a path to ruin for all.

To extend the analogy, Congress hasn't had their balls removed, they simply aren't humping other dogs right now.

I'm not an expert, but while many of SCOTUS' rulings have been against the plain letter of the law, few of the decisions ruled out Congressional power in those areas categorically. Congress could pass a new Voting Rights Act, or redefine the EPA's powers over wetlands, or any number of things, they just choose not to. And of course, even with a Democratic Congress, getting past the veto may be impossible.