It won’t happen.A Federal judge (Rat appointee) will block it in time to make it impossible for 2020.
This is going to be fast tracked right to SCOTUS. Might as well have the 9th Circuit start drafting their reversal of the policy change, stating that it’s unconstitutional for the federal government to want to know if you’re actually a citizen.
Then, just have all the lawyers hop a, Red Eye, to DC and meet at the Supreme Court the next day or two.