I know that terrain is a major blocker of signals, With Donald Trump building a wall on the Mexican border, Tijuana, Juarez, Mexicali, etc.'s border blasters may not be able to get a signal into their primary sales markets on the opposite side of the border. This scenario gets even more intense when stations like XHTO, XHRM, XETRA and XHMIX are the only stations in their respective core sales markets (El Paso, San Diego, San Diego and Yuma-El Centro respectively) with the format they provide. Thoughts, anyone?