No. Declaration of Emergency allows him to immediately spend the non-Declaration $.
Second, it alerts the hysterical types in his base that in fact he knows what he’s doing.
Third, correct: with each MILE of wall that goes up, the funnel grows smaller, i.e., the miles you have to patrol. So all the hysteria about not having more border patrol agents is misplaced. You don’t need more if you are building wall. In fact, over time, you need fewer.
ping