Even during periods the British government gave the security forces carte blanche, and eventually they forced a political settlement. If you don't like that example, there are dozens of others that are equally instructive. Any place where a bunch of ill-equipped people are giving a fairly modern military force a run for their money has lessons to teach. If you prefer fiction, start with John Ross' Unintended Consequences . That is a wager I would really rather not see tested if you don't mind.
Events are far too likely to get very ugly for everyone if that sort of thing starts.
Every lunatic with a score to settle against anyone or a grudge of some sort will come out of the woodwork and join the carnage. The surest way I can think of to ensure that the rather dire scenario I outlined above happens is to keep reassuring the tyrant wannabes that they have nothing to fear. I want those fear-mongering statists to gibber in terror and wet their pants at the very thought of daring to push around any American citizen. Or, for that matter, any free person anywhere in the world. The whole point of the rule of law is to prevent things from degenerating into that sort of chaos.