Maybe Trump is just doing this in a step approach. Many illegals would self deport of put on such notice — at least the duds who are. Here just for the welfare.
A step approach is indeed the best, or, ONLY way, to get anything done.
Secure the border is step one. Without that, nothing else matters, period.
Then stop the hand outs and watch millions leave on their own.
If all we ever did was those two things, the issue would be 75% solved in a few years. We hardly ever solve anything that well.