It's happened before, both recently (since 2001), but Executive Order 9066 happened over 80 years ago, in the 19th century the US literally passed a Habeas Corpus Suspension Act.
America puts too much faith in its courts and constitution.
One of those cases where it's very, very important the "the government" isn't a unified block, but a collection of a very large number of staff spread across a very large number of organizations. Only some of which have gone rogue.
The people who are out here saying "totalitarianism was the inevitable consequence of federal standards for feces in bologna" are exactly the problem in America today.