I think clear thinking Americans understand the wall itself is useless in it's physically planned form. Unneeded to do what it's supposedly meant to do. On the other hand the message it sends is good and needed. While the Mexican government passes out fliers on how to enter the US...and I say enter when really it's invade.
The big problem is that at some point liberals will lie, cheat and steal a representative into the Whitehouse again in the future. And if there is a wall at that time, they'll just turn a blind eye to those crossing over it like the past 8 years have shown us. The key to fixing America is to muzzle those who have a hard time telling the difference between fantasy and reality. THAT is what Trump should be working torward.