Secret is Being Positive
This is an idea that is plausible. 

All borders are shut as of today. Those within US boarders have a choice. This is your new country, or not; one and only. If you were not born here you will be given an ID. Everyone is given an American birth certificate. 

Now if you don't want to be here then leave. Because. with a unifying factor to rid the nation of Met to Heroine communities grow.  Houses are circled by 100 men to rid the scourge.  Itr is a unified effort. All races and religions fight this cancer.

The schools teach alternating days English & Spanish.  If you hate us here then leave.