We’d have to build walls around all the major cities. It’s not as simple as a north/south split.
Well, you’d have to give people a choice of where to live, after you send all the current illegals out-but that is not such a big deal-stay in the “red” country, there is no more free ride-if you are in need, you go to a private charity/church-that is why they exist, and why we do our Christian duty by donating to them/
Then you’d have to set up borders with the blue states, have border patrol on them, and have to deport our one-time fellow countrymen-too damn bad-if they are liberal lunatics, they’d be better off in California and the rust belt anyway.