I can guarantee you, there are PLENTY of “OTM’s” in the area!
The Mex get detected most easily as they refuse to make any effort at assimilation.
Illegals from other parts of the world either try to blend in, or rarely leave their ethnic enclaves. (”Chinatown”, “Little Havana”, Dearborn, etc.)
Sheriff Joe needs to bust a bunch of OTM’s if he has not already done so.
I don't think Arpaio needs to do anything other than what he is already doing...executing the law as written. Obama is out to shut him up so will find fault with anything the sheriff does.