"How is enforcing our borders somehow unjust?"
My 4 immigrant grandparents came from 4 different countries.
They received their citizenship papers the moment they steeped off the ferry boat that brought them from Ellis Island to Manhattan.
Two others whose names you might know also benefited from that policy - especially in light of the recent Independence Day celebrations.  John Philip Souza was Azorean Portuguese, and Irving Berlin was Eastern European Jewish.  What songs are more all American than "Stars and Stripes" and "God Bless America."
How many more like them are we excluding?