This would be equivalent to deporting all the citizens of Minnesota (about 5 million), Iowa (about 3 million) as well as North Dakota (634,00) and South Dakota (652,000). This will not happen!
It is virtually impossible to identify and deport 8-15 million men, women and children. The President's proposal seems modest to me, but it could be improved by a tough proposal to tighten border security. The President is just not going to let this slide like his predecessors. Bully for the President!