Mexico is an enemy of the United States and really should be treated as one.
Since they don’t respect our sovereignty, neither should we respect theirs. Send the U.S. military in to obliterate the drug cartels, no matter what it takes. Maybe while they’re there, repay Mexico’s insolence with some “reverse remittances” by seizing part of their oil production and using the proceeds to repay the U.S. for all the damage they have done to us. Then seal the border and make it crystal clear that anyone attempting to cross it illegally will be shot on sight. Oh, and implement the tariffs that Trump threatened on Mexican imports and make them permanent.
And this would all be after we’ve rounded up every last illegal in the U.S. and dumped them in Mexico, along with pamphlets directing them to whatever social services Mexico has.