One thing to note when talking about "foreigners" is that many rights in the constitution specify "persons". So citizens and non-citizens theoretically have equal rights from that standpoint. So I agree in general but it's worth noting that he was supposed to have constitutional rights to speech and against unreasonable searches.

Yes, sorry, by foreigner I mean non-citizen.

Others do have constitutional rights, but the legislative and executive hold plenary powers in the realm of national security and immigration.