In my Alternative Republic, citizens would have constitutional legal protections distinct from non-citizens. Due process for one group would not be identical to due process for the others.
If you were found in the AR as a non-citizen and were unable to provide proof of legal presence within 48 hours, you would be immediately deported. No appeal. That's for a first offense. Second time, a couple of years at hard labor, followed by another deportation. Third time you come in illegally, you don't leave.
If a country cannot --or will not-- control its borders, WTF is the point of having a country?