I was stimulated by this issue and then read an article on Trump's wall in the New York Times.
It's not really a wall that Trump is after, if indeed it ever was. In my opinion it's a show of his might, it's a proof of his potency.
Trump spoke of a "crisis of the hearth and of a crisis on the soul". He mentioned drugs, crimes. It was an epic threat that he painted and a grossly exaggerated one. Whatever it takes to deliver on a promise that he should never have made. In my opinion,Trump isn't selling something that the country really needs and that's why he and his allies have laid the pitch with lies. He widly infilates the amount of crime committed by undocumented immigrants and just widly overstates the effect a border wall might have on the country's opioid crisis.