This cloddish meander along the Mexican-American border from the Gulf to the Pacific just goes to show (again) that it takes a writer, as well as a subject, to make a book--and a little extra imagination and judgment when the subject, as here, is not precisely defined. In the 2000-mile border strip, Miller found ""gangsters and smugglers, cops and con men"" (as he himself sums it up), along with the equally notorious contrast between haves and have-nots. One of his chapters details, to some point, the runaway success of border radio's huckstering cowboy evangelists; but any shady business will do--including the ""Confessions of a Parrot Trooper,"" about parrot-smuggling. (Miller is the author also of The Assassination Please Almanac.) True, we meet some displaced Indians with real problems and hear the story--a civil-rights scandal--of the Hanigans' sadistic assault on three Mexican ""wetbacks,"" and how they got off. But most of this recital--jogged along by Miller's hopeful purchase of lottery tickets--is little more than a hit-or-miss guide to local crime.