‘I assure you, as often as you did it for one of my least brothers, you did it for me.’ (Mat 25:40)
Is this Jesus teaching only for the Jews?  I am sure the majority of these illegal Mexicans are Catholics.  You are not a Catholic or a Christian, are you?  Or you being a American citizen comes first and being Catholic second? 
“So we, who are many, are one body in Christ, and individually members one of another.” ( 12:5)   Is this teaching apply to the aliens, then?