@realjohnboy,
Tough questions. I doubt Hispanics have any groundswell feelings against legal immigrants, though there is room for individual variation. I'm sure what you suggest is not unknown, but I just don't think it's going to be even remotely decisive in a political sense. Truely, I see no political advantage in Martinez's following through on this.
The only certainty is that Navajos don't like "Mexicans" - the quotes because anyone with any Hispanic ancestry is taken to be Mexican. Just in my personal experience, that's the only strongly held feeling in my own town, which is about equally divided between Navajo, Hispanic, and "Anglo" - Anglo being anything Northern European.
ETA: I don't see any political significance.