for the umpteenth time, read the Constitution... I assume you have heard of that document. No dem wants terrorists in the US, to think otherwise is patently stupid. For anyone accused/taken in by gov what is Constitutionally required is due process, aka "your day in court". We are fighting illegality done by the government, not the criminals.
"No person shall be .... be deprived of life, liberty, or property, without due process of law" (5th Amendment). What parts of that are you unwilling to allow into your consciousness?
"How can Americans feel safe knowing the guy next door could be a terrorist or killer or foreign gang member?" Stupid once more: YOU could be a foreign gang member. YOU could be a terrorist. If I am an officer in ICE and decide you are one or the other, without any court hearing, without any charges, you'd be happy with me bundling your ass off to some Salvadoran prison with zero rights to attorney, hearing, contact with family, etc... a black hole.
We have courts and procedures to decide these things. You would applaud Gestapo for rounding up, imprisoning Jews without trial or charges. It is the same thing, the same lack of rule of law.
Cut the crap about dems wanting terrorists etc. It is BS and you know it. If you don't, seek deprogramming