Because we've seen the puppet show. Over and over again.
Trump might make a show about using the military to build the wall and then a Federal judge will step in and stop it before the first shovel is used.
Then Trump will whine at a rally about how mean the courts are to him.
Instead of using thumb screws and pushing legislation.
No court can prevent him from using the military. You guys think because a war takes a long time to win, it is unwinnable. And Trump doesn’t whine and the Courts have blocked his legit efforts.