Let’s say Trump gets his Wall, every democratic POTUS candidate will campaign against it. Eventually a Democrat will be President again and will score the easiest political points by halting construction or tearing down the wall making this all a waste of time on money.

This is why consensus is important because the other side will just tear it down the minute they are in power like Trump did with Obamacare. The wall and Obamacare are both bad policies trying to be forced through… take a hint.