We already have no go zones for illegal immigrants. Called sanctuary cities. Local police are not allowed to detain and implement expulsion of criminal illegal aliens. Most of whom are Mexicans with Central Americans in second place
The "sanctuary city" I worry about the most is LA. The critical national infrastructure which runs through what mae be territory under insurrection is vital to our economy. The refineries and ports (LA and Long Beach) and their pipelines, road and rail links will all be in "rebel territory" if TSHTF.
My fear is that during any coming deep recession, when Americans will demand that NO jobs go to illegal aliens, the millions of illegals in LA will be unemployed, but will refuse to go home to Mexico, where the economy will be even worse. Millions of hungry illegal aliens in the LA area will have one powerful "weapon" to yield: threatening the smooth running of the refineries, pipelines, port operations, highways and railroads through "their" territory.
That is a recipe for a major explosion, especially since it will happen when the national economy is already a shambles, and we will need those refineries' output and so on.