Before people talk about aliens - Covenant are a non-human expansionist empire. Immigrants are other humans. The idea that humans would deny entry to OTHER HUMANS, immigrants and refugees because of skin color of language would be insane to him.
You.......you do know what Master Chief's original purpose is right????? It was to kill people rebelling against the UNSC that's why the Spartans were created......... he would never kill someone working for the government because he kills people fighting back against it