My original comment is not, as suggested by a couple of posters, meant to come anywhere close to questioning the need to welcome immigrants or to create a more rational and humane immigration law.  
I believe that words should be used to used with precision.  In this case, refugees are a particular subgroup of immigrants; they undergo an especially rigorous screening and then get certain benefits not accorded other immigrants.  Because current refugees are often Muslims and there is much prejudice against them, it is important to remember that this group gets special scrutiny and has special needs.  
The definition of refugee is very limited, so I believe that it's important to use the word correctly.
I believe that "stranger" in the Biblical context refers to all immigrants, not just refugees.