You seem to be radically misreading a condition on conditions at birth that applies to birthright citizenship clause of the 14th Amendment as a modifier on conditions at the time of government action against them that applies to the due process clause of the same amendment, but also, the 14th Amendment has no bearing on whether people have due process rights against the federal government, in the first place, as the due process clause of the 14th applies to the states.
Due process against the federal government is provided by the 5th Amendment, so even if the misreading of the 14th was right and applicable to due process rights, it would limit only the due process applicable to certain people for actions by state governments.
> Lets also not forget how much legal precedent Guantanamo provides when dealing with non-citizen (or even US Citizen!) "terrorists".
Well, yeah, but most of that legal precedent was negative for unchecked executive power (and even restrictive of legislative abuses), see Rasul v. Bush, Hamdan v. Rumsefeld, and Boumediene v. Bush, most notably.
