The point is that he's proven that his claim of deporting "illegal" people has no meaning at all. When faced with the fact that the Springfield migrants are objectively not illegals, he put the goalpost one step back and claimed that their being legal was illegal because something something Khamala Harris. So if we can conclude that actual legal status will not be a factor in his musings about who is and is not illegal, the only prediction that can be made is that his plan is to deport anybody he THINKS SHOULD be illegal and I would not mind betting that his criteria will coincidentally encompass the racial minorities he dislikes, regardless of what previous laws considered legal or not.