Isn't the immigration law a federal law, and thereby enforceable by federal troops.
Seems I remember hearing recently that the ACLU and Mexico were upset with the Sheriff in Arizona who is arresting illegals based on the new smuggling laws. They thought he should not be enforcing federal law with local officers.
"Isn't the immigration law a federal law, and thereby enforceable by federal troops."
Posse Commitatus prohibits the use of federal troops in law enforcement, local, state, federal. PC does not apply to the NG since they are under state control, not federal.