That and visa entry exit tracking could be implemented much faster than a wall could be constructed and may have as much or greater impact. A wall is a fine idea, but I thought it odd that it was by far the most talked about component during the campaign compared with other deterrents.
My thoughts as well. In this age of computerized everything, it should not take much to track visa entry/exits and issue a bench warrant for the overstays. Penalties would include disbarment for ever entering this country again. Akin to self-deportation in some/many cases.