This is only sorta true.

They have jurisdiction over TRUTHSPEAKER, because that is a legal fiction they created when they got your birth certificate.

Also, when you are in a court of the bar (there are no USA courts) the judge has complete control over that land. So, he/she can imprison you for anything. The easiest being contempt.
And you consent to this when you rise. The bailiff says, "all rise, the (dis)honorable high muckety muck is presiding." You just gave consent to the bar to pass judgement on you.

So, although what is above is absolutely true, the reality is there are people who will beat you up for not going along with the play.