There's some limit to these powers, e.g. a quarantine in SF in the year 1900 was struck down as being racially discriminatory in a way not justified by public health (only ethnic Chinese were quarantined). But courts are reluctant to second-guess this kind of thing unless it seems like a pretext.
There's no such thing. The idea that a right is inalienable is aspirational. While we should respect it, we should also respect that nothing is absolute and the best laid plans of mice and men and whatnot. We cannot allow perfect to become antithetical to good.
The virus poses a larger threat to national security than the Viet Cong, after all.
I'm sure Earl Warren said that to himself when he locked up the Japanese Americans during WWII.
Especially when the country isn't even sure about bump stocks.
How about we address such things on a case by case basis?
Yes it does. This is war.
But in a way, you are right. We are in a war for our futures, and we are losing.
I mean, it does until challenged, and it could impose restrictions on entering government buildings -- but the government really doesn't have an unlimited authority to declare arbitrary restrictions on the right of people to peaceably assemble.
Not legally, anyway.