I am sure you meany in jest , seperating familes and uncertainty for the dreamers or illegals who had kids born in USA.
I am no advocate of illegal migration but can imagine many folks will be terrified, though I doubt unless they really "seal the S border " how it can stop when we compare poverty in Latin rural slums with even min wage life in USA.
They could close teh entry points to all non US citizens or bona fide "Tourists with pre approved Viusa , Money Onward ticket just like here"
However I cannot foresse many real US citizens queueing up to be knockers, pool cleaners maids and gardners for teh fat cats, a pool of cheap or better undocumented cheap labour is great to supress all wages and control US workers.
Of course there are some alternatives , like criminal sanctions for landlords drs hospitals taxi firm who emply illegals cheap or I saw a gung ho Maga type solution is to put a bounty! on delivering Mexican or Canadian illegals to the border? Not sure how they will deport folks to places like Cuba which may refuse landing ?
The irony is the WASP hegemony is waning and their forebears too were undocumented when they violently dispossessed the native Americans. From ocahntas to Pucker Hunters what a mess.