I think they do- but we are so far removed from people actually caring about providing a credible threat as of now. Once people lose their access to basic amenities though, everything changes. And the type of people that do see the government as a threat now, already have organized militias, rudimentary training, military connections, and stockpile weapons and food. The right to organize into a militia is a constitutional right, and extremist elements have certainly been taking advantage of that.

And logistically speaking, we have very porous borders and inevitably foreign entities that would seek to assist an insurgency. The American Revolutionaries had the support of the French, and the Southern confederacy had the support of the British.