Solution: 70 million, to be chosen by lottery (or perhaps chosen from the ranks of lottery players) are hereby ordered to report to designated locations so that their Surplus status can be rectified.
From this point forward, for each child born, or for each person entering the country legally, someone else must report to a Surplus Status Rectification Center. Anybody entering the country illegally is automatically designated Surplus.
Someone oughta make a movie.
Seriously, though, someone is significantly underestimating the carrying capacity of the USA.
Been there, done that.