I have one word: Deportations.
I have another 2 words: Wall (NOT FENCE)and Minefield.
deport ALL illegals, build the wall (concrete, extending 20 feet below ground and 15 feet above) , electrify it, top it with razor wire, build guard towers with machine gun posts along the wall, lots of sensors, camera, guards, etc, and a minefield in front of the wall.
let's see if THAT decreases illegal immigration.
Sure...
Living inside a bunker is a much better idea then simply punishing the American traitors who line their pockets hiring the illegals ...