#immunity 
Discussion
America used to only have a Sheriff. His job is to help manage those of us that are "domiciled" Citizens of our Union state. Not "residents".
After the 14th Amendment created a 2nd citizenship...a Federal citizenship, better known by its euphemism "a US citizen", then POLICy Enforcement (POLICE) was introduced to manage "that" citizenship group.
USA Citizens are still protected by the Constitution.
SCOTUS ruled that U.S. citizens "may" be extended the same Bill of Rights, but that's on a case by case basis. It's not the same guarantee the Constitution gives its Union state Citizens.
what if citizenship is revoked - who protects?
Only Federal citizenship can be taken away. You aren't born into it. You "naturalize" yourself into it when you sign under perjury that you identify as a US citizen.
You are born into Union state Citizenship, and nobody can take that away (lawfully).
By the way, whereas Union state Citizens have the 9th Amendment of innumerable Rights beyond the pursuit of happiness, Federal citizens have obligations...like paying the income tax, for example.
Someone would only want to have their optional Federal citizenship revoked. But Union state Citizenship is all benefits without the innumerable statutory obligations.