Sheriff West and his deputies in their F-150s escorted me to a godforsaken spot sixty miles southeast of El Paso. In his Texas bowl hat and deeply lived-in jeans, the man seemed to have stepped right out of Central Casting. Never less than poker-faced, the good sheriff said no more than he had to, and when he did speak it was to the point. "You're an idiot," West said to me casually in his monotone Tex-Mex drawl as I scanned the border country through...