A decent border fence/wall with surveillance would cost around 8 billion to build, based on construction estimates I've seen.
WHY NOT HAVE THE ILLEGALS BUILD IT TO PAY OFF THEIR FINES AND THE COST OF PROSECUTING THEM?
right. Have guys in orange jump suits and ankle chains operating excavators, dozers, dump trucks, post drivers, and etc?
Very little border fence work could be done by unskilled labor, let alone those that were being forced to do it with no wages.
Entertaining thought thouh! ;^D