While it is fun to speculate about what the Hollyweirds of Malibu and Bel Air would do with a howling mob pitching tents and defecating on their front yards, I would much prefer the foreign invaders are shipped back to Mexico to await their asylum hearing in 6-24 months. Most will never show up and if they sneak across again they might well destroy any hope of remaining.
That is the key: get them frustrated and disillusioned about ever coming to stay in the US except if it is legally adjudicated. Living in the rough on the south side of the border will send many of them off to less harsh environments, preferably back where they came from.