That being said, we should still build a border barrier. Now it might be possible to argue that there are a few hundred wilderness miles where it isn't worth it. Then let's build the first thousand miles and see whether we've hit the point of diminishing returns. We will still need observation of the fence and guards to quickly return those who crossed, or else the wall will just be an obstruction to take a couple extra minutes to cross. But the wall shows that there is a new seriousness about the issue. Also citizen videos of Mexicans climbing it with no repercussions will embarrass an administration far more that videos of the same Mexicans just walking across the border.
They probably won’t go over it...but under it.