Some Republican legislators in Arizona have proposed an alternative to Kyrsten Sinema's recent proposal:

A group of conservative Republican state lawmakers want to classify as domestic terrorists protesting illegal immigrants who "intimidate" or "threaten" U.S. citizens.

The GOP bill would also classify members of Mexican or other foreign criminal gangs or drug cartels as domestic terrorists and classify violations as felonies.

The measure defines domestic terrorists as persons who are illegally in the U.S. and are part of criminal enterprises as well as protesters whose actions intimidate, threaten or cause physical harm to legal citizens...

It appears like this might be on less shaky ground from a constitutional standpoint than Sinema's bill. AFAIK, even illegal aliens have a constitutional right to protest. However, they're adding the "intimidate, threaten or cause physical harm" bit, so it might be OK. And, of course, expect the ACLU - a group indirectly linked to the Mexican government - to fight this tooth and nail.