Well, let's look at that.
Rounding up people and sending them to concentration camps (whether called "reservations" or "relocation centers"). Check. (Treatment of Native Americans. Japanese-American "Relocation Centers" during World War II).
Illegal medical experiments involving infecting people with diseases, not treating them, and observing the effects done on people without their knowledge or consent. Check. (Tuskegee Syphilis Experiment--and particularly interesting how that was "explained" to the victims as they were getting free health care from the US Government.)
Arbitrary searches of American citizens' households aimed at the seizure of property without either probable cause or any kind of warrant. Check. (post-Katrina gun Confiscation)
Laws passed allowing the indefinite detention of American Citizens without due process of law. Check. (NDAA 2012)
American citizens going about their daily business being stopped and searched again without probable cause or any kind of warrant (or even the "reasonably articulable suspicion" for a "Terry Stop"). Check. (TSA, not just at Airports, but at bus terminals, rail and subway terminals, highways, even High School Proms.)
"Can't happen here?" It has and is happening here.
Tell me again how the Second Amendment is obsolete since it's not needed to defend against tyranny.
But "Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed."
Yet, still, "But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security."
Addendum Chicago police are instructed to shoot people for obeying the law. Background: Illinois, the last state in the Union with no provision for legal handgun carry for self defense, had its "no carry" law struck down and was given a timeframe in which to come up with some kind of carry law before the existing law went away entirely. So, Illinois now has provision for concealed (or otherwise) carry or else have no restrictions on carry at all. But the Chicago police Chief vowed to train his officers to shoot people obeying that law.
Addendum 2 EPA exposes people, without informed consent, to high levels of toxic chemicals to track the effects.