Due process cases are fact specific, and I am not privy to information NJ authorities had before them or their decision-making process. However, it is highly unlikely that she will prevail.
While the Supreme Court has long held quarantines to be constitutional, it has not ruled directly on the scope of permissible quarantines. However, in the famous case of
Jacobson v. Massachusetts, the Court did uphold a blanket mandatory vaccination law, under which resisters were put in jail. The principle here is the same as with quarantine – that one’s normal rights to bodily integrity are suspended by a general and serious public need, especially of an epidemiological variety.
Still, in part because quarantines have rarely been imposed since World War II, there is relatively little direct precedent on their permissible scope and circumstances. But a brief review of the cases suggests it extremely difficult to challenge such an action without a clear showing of medical unreasonableness, or discriminatory application. Indeed, I found no cases in which a quarantine has been lifted due process grounds (though there have been some successful challenges to conditions of quarantine).
One case upholding a quarantine has facts that look strikingly like Hickox’s. In U.S. ex rel Siegel v. Shinnick, 219 F.Supp. 789 (E.D. NY 1963), the plaintiff was confined for 14 days on her return from a “smallpox infected area” abroad, despite a lack of any evidence of direct exposure or symptoms. The court upheld the action, noting:
[The] judgment required is that of a public health officer and not of a lawyer used to insist on positive evidence to support action; their task is to measure risk to the public and to seek for what can reassure and, not finding it, to proceed reasonably to make the public health secure. They deal in a terrible context and the consequences of mistaken indulgence can be irretrievably tragic. To supercede their judgment there must be a reliable showing of error.