As always, I welcome any corrections from those who think they can keep this shit straighter than I can, but the gist as I understand it is this:
Many of them actually believe the entire legal regime of the united states is actually a function of private commercial law and that the "real" government is a sort of suppressed by a corporation that was created under its rules, so if they can successfully opt out of their involuntary commercial relationship with the "Corporation" that they are not bound by its rules, including taxes. Because they're so very smart, they understand you have to be careful, so making sure that you explain that you're not engaging in "Commerce" as the corporation's founding document states is important so they don't rope you back in. The US Constitution gives the federal government the right to govern "Interstate Commerce" so in the spirit of the law being a series of magical incantations, they want to keep consistent. The various US states are either in league with, or under the thumb of, the "corporation."
Sovereign Citizens are mostly a US thing, but not entirely. When COVID hit, there was a video floating around of what was essentially an Estonian sovcit. Among other things she claimed that Estonia was actually a corporation registered in the US, etc. And no corporation can tell HER to wear a mask in the grocery store
LOL. I suppose if anything, there's a hint of unwarranted optimism in their belief that all their frustrations with the modern world are just one confusing layer deep, and all they need to do is scrape the dirt in just the right places and a logically sound and egalitarian utopia will be there for them.
I can retain just a bit of sympathy for people who sort of intuitively, even sub-consciously, realize that it's bonkers for the richest country in the world to have an utterly inadequate social safety net and for life to be so expensive. The response, though, is not useful or reasonable, and I reckon most of the ones who bother to vote will likely vote in a way that forces the Overton window to the right.
Then there's the assholes who just want to skip out on child support or debts that they can good god damn well pay due to the benefits they've already accrued under the current system.