@Merovius
The biggest turning point here in the US was 9/11 and the patriot act. That was when a lot of rights were removed from citizens but I think it's been brewing since LBJ after JFK was assassinated.
The thing about US authoritarianism is that for most of it's existence it grew inside of corporate America who, in pursuit of profits, infiltrated politics. Most didn't realize this and continued to support companies who did the wrong thing. The misunderstanding that we voted only in November and not every day with every dollar we spent was key... And sadly many still don't understand this.
@alexwild