I first became aware of "DREAMers," or specifically people in circumstances we associate with DREAMers (they weren't called that of course), when I was in grad school. A friend of a friend was doing a dissertation (sociology I think?) about them. That area (parts of Rhode Island, Massachusetts, Southeastern Connecticut) historically had a lot of immigration from native Portugese speakers, including people from the Azores and Cape Verde, some of which continued into the present. So there were a lot of "kids" who had been brought here when young, never naturalized, got in a bit of trouble with the law, and were deported to places they had never been to. Also they often didn't really speak the language, certainly not fluently and certainly not formal and written forms of the language with any skill. They spoke enough to communicate with their parents and that's about it (this is common for immigrant kids from everywhere).
Anyway, the point is that not that these people (now adults!) are immigrants from Mexico or wherever, the point is that these are Americans who lack papers. They have no other home. They don't have a home country. And many don't really speak Spanish or anything else other than English. Stop peppering political speeches to them with Spanish. It's missing the point.