[USNBandit]

That would require tracking visa overstays. Which we could do with an app on a phone. Stop checking in, we hunt you down.

It will take years to build a wall. A lot could be achieved while waiting for the wall to be built.

[ichabod1]

The wall is a metaphor for enforcing the law. Starting day 1 ice and other feds will be instructed to start doing their jobs or go home.