How to pay for it?
Simple - confiscate the property of the people who invaded the country when you deport them.
It is that simple.
If the issue of breaking up the family comes up, remind them that they are equal to any American who commits a crime and they are put in jail without a concern for their family so it is fair to deport the entire family.
Other countries do the same thing, I know of some who lived in France, their parents were from Germany but never applied for the permits to live in France and they got booted even though the kids were born and raised in France.
We need a real border, like i have said using eminent domain take the land from the ranchers and anyone else from the coast of Texas to the coast of San Diego and build a 300 foot wide ravine with a wall on one side and bridges every 500 or so feet.
That is a border.
