Can the government quarantine people without proof of contagion and imminent assault? The short answer is no.
We know that, under the Fifth Amendment, if any government — state or federal — wants to impair the life, liberty or property of any person, it must follow due process. Due process has two components — substantive and procedural…
Now back to our question of whether the government — state or federal — can confine persons against their will in order to protect public health. The short answer is yes, but the Constitution requires procedural due process. That means a trial for every person confined.
Thus, a government-ordered quarantine of all persons in a city block or a postal ZIP code or a telephone area code would be an egregious violation of due process, both substantive and procedural. Substantively, no government in America has the lawful power to curtail natural rights by decree.
Procedurally, notwithstanding the fear of disease contagion, the states and feds may only quarantine those who are actively contagious and will infect others imminently. And it must present evidence of both at a trial at which it bears the burden of proof.