What do we expect when we've been letting millions of freeloaders from Puerto Rico do the same thing for 100 years?
Puerto Rico is a Territory/Commonwealth of the United States. Mexico is not. I personally think Puerto Rico should have been cut loose many years ago- but that is another issue. As long as they have the status they do now, Puerto Ricans can legally come to US.
Many Mexican citizens can legally come to the US also; in fact we allow more Mexicans to legally work here and legally live here than we allow from any other country. I am not concerned about anyone who comes to this country LEGALLY. I am concerned about all who come here illegally.