And if the particular governmental system that is the US federal government was in fact destroyed and rebuilt from the ground up, why would the set of people who are currently legal citizens, legal permanent residents, and legal immigrants remain the same as is today under the laws established by that system? If the US Constitution is moot because there's been a successful military uprising against the US federal government, and people are sitting down to write a new constitution that will actually establish the rules of governance for (some subset of?) the land area of the current United States of America, why would that new constitution have the same rules governing illegal immigration enforcement as the current one? Before citizens can protect themselves from the government to be a successful democracy, they have to decide who is in fact a citizen who can legitimately vote in that democracy.
I think this assumes a scenario where the past ceases to exist. However democratization and transitions back to democracy are built upon on taking the past and building it better. Brazil and Chile did not christine a state of no citizens when they returned to democratic forms of government.
I don't see any benefit to not determining everyone who is in an area at a specific time a citizen or eligible for citizenship.
