I have a slightly different take. I think people who immigrated here legally and have permanent resident status but do not wish to become US citizens, like our German compatriot
@HansGruber, should be able to have guns.
I actually have a German friend who has been here for about 40 years now. I haven't seen him in probably 15 years. He's a school teacher and a gun enthusiast with many very cool guns. He didn't want to give up his German citizenship so he refused to become a US citizen. I have no problem with him having guns. Where I'd come down on his constitutionally protected 2A rights is a bit muddy. As a general rule I do not subscribe to the theory that non citizens have the same constitutional rights we do. But, there is a difference between people who came here the right way and "Undocumented" people.