Neo realism: illegal immigration as a security issue

[Villareal]

If anyone can, would someone please provide a basic backgrounder about
neorealism; its primary tenets, etc...

My argument: Illegal immigration is gradually being labeled/recognized as
a security threat to the U.S. As a security threat, the U.S. has enhanced
its law enforcement efforts toward controlling illegal immigration. The
enhancement includes an expansion of arrest authority for immigration
officials and the relaxing of constraints upon military involvement. Is
there anyway of making this fit within the neorealist paradigm?