Well, that is one of the meanings of sovereign. It’s also a UK coin. And, in the use of the word here, it means a group of people who are their own authority.
Basically, you are getting caught up in the etymology of the word.
Pfft. So what? I am Napoleon Dynamite. Gosh!!
Leaping Lizards, the right-wingers sure have a monopoly on the morons, criminals, losers, degenerates, scumbags, …don’t forget the idiots!!! Please, lets help them succeed! Lets round them up, and put the in some barren patch of America where we can fence them out of the rest of the country!!! Pen them up, and pull the plug on all services! They can all become hunter-gatherers!!!