Peter Laufer and Lee Morgan II each spent decades along the Mexican–American border, but there is nothing to suggest the two men ever met. They lived in very different worlds.

One was born in 1950, the other in 1951, and both baby boomers believe passionately that American policies governing our southern border, the immigration of Mexican workers, and the so-called war on drugs are bankrupt. Both make persuasive arguments that officeholders and agency chiefs care more about their political careers than about addressing on-the-ground realities in ways that might alienate voters.

But that is where the two men part ways, their viewpoints diverging like two sets of footprints in the lawless borderlands they know so well.

Mr. Laufer, born in New York, is bearded and Berkeley-educated, an award-winning documentary producer and former NBC News reporter. He also is the son of an immigrant father who made landfall at Ellis Island in 1923. In “Wetback Nation: The Case for Opening the Mexican-American Border”(Ivan R. Dee, 246 pages, $26) he calls for a complete opening of our border with Mexico and unrestricted entree for any and all Mexicans who wish to enter America.

Controversial by design, “Wetback Nation” offers a refreshing counterpoint to the current election year posturing that fences in the immigration debate in Washington, a polemic that inevitably will lead nowhere as both political parties vie for votes in November. “Opening the border to the free passage of Mexicans who wish to come north is the only reasonable and longterm solution,” Mr. Laufer writes.

Open the border to the people who are coming no matter what we do —people we want and need, no matter how much we may say otherwise. Once the Mexicans travel north freely, the real bad guys can no longer hide in the shadows. Over time Mexicans and Americans will learn to blend, not collide.

Mr. Morgan is a native Texan, a fact he considers so important it’s stated in the opening line of his memoir. He swears like a noncom and favors, um, colloquial grammar, traits that irritate: “It’s their piss pot of a country and we can’t say shit about what goes on from our side of the border.”

But then you come to understand that reading “The Reaper’s Line: Life and Death on the Mexican Border” (Rio Nuevo, 525 pages, $25) is akin to sitting next to guy on a barstool who does all the talking and happens to tell damn good stories, however embellished and unedited.

Perhaps no editor had the nerve to clean up his copy. Mr. Morgan, you see, is, or was, a killer, which lies at the heart of his own John Wayne-like, good-guy identity. A sniper in Vietnam whose squad was named the Grim Reaper, Mr. Morgan survived to spend 28 years as a gun-toting customs officer, much of it in the heartless Arizona desert.

He writes melodramatically about the inner Beast and Reaper that lie within all men who kill, including himself. Mr. Morgan recounts his boyhood experiences learning to shoot firearms in East Texas, courtesy of his childhood hero, a disciplined young ex-Marine and sharpshooter named Charlie. The quiet, somewhat tightly wound Charlie turned out to be Charles Whitman, the infamous Texas Tower Sniper who killed 16 and wounded 31 others on the University of Texas campus in Austin in 1966, a spree that ended only when officers climbed the tower and gunned him down.

Mr. Morgan, by the way, does not like people like Mr. Laufer, except when their stories happen to capture law enforcement officers in all their glory. Mr. Morgan learned of the massacre after returning home one day: “(T)he house was surrounded by news media assholes. I had never been to a full-fledged circus, but I imagined it couldn’t have much over the show I was witnessing … A microscopic mite couldn’t have gotten through those bloodthirsty buzzards.”

He doesn’t like bosses, either. Reporters, policymakers, superior officers holding down desk jobs, Yankees — they all fall into a single category of wimpy, misguided second-guessers known as “REMFers,” a derisive acronym Mr. Morgan picked up in the military. Mexicans — some of them, are good, hard working people. But Mexico the country is a corrupt cesspool, the stink pervading all aspects of life and society on the other side of a border Mr. Morgan seldom crossed, according to the author’s own words.

What makes Mr. Morgan readable, in the end, is his authenticity. His memoir has a terribly coarse quality that is genuine, effectively conveying exactly how people like himself think, speak, and act when reporters, bosses, and other human inconveniences are not within firing range.

It isn’t likely that Mr. Laufer ever sat on a barstool in the same joint as Mr. Morgan.While the customs officer spent his nights staring through night vision devices, laying in ambush for drug smugglers, his finger on or near the trigger, Mr. Laufer was ambling across international bridges in khakis, watching immigrants slip through the other way, pausing to enjoy a margarita, the language, and the street life on the Mexican side of the border.

Mr. Laufer writes with great empathy about the invisible but essential class of Mexican workers in our country, whose sudden absence would bring the economy to an abrupt standstill. While Mr. Laufer hopes his book will become part of the national conversation about immigration reform — a highly unlikely scenario with about as much chance as legalization of marijuana — he does succeed in putting a human face on Mexicans who risk everything, including their lives, to sneak across an often deadly border in pursuit of better opportunity for themselves and their children.

Anyone vaguely familiar with American policies since restrictions were first put in place in 1917 knows current enforcement practices have choked off illegal crossings in densely populated urban areas and forced desperate migrants and their smugglers into the desert, where hundreds, perhaps thousands, of Mexicans have succumbed to the elements or fallen prey to the very people they paid to help them make the crossing.

Messrs. Laufer and Morgan have good stories to tell, and both come to their passionate positions through the lense of their individual experiences as witnesses along a border most Americans will never visit or cross.Yet what happens on both sides increasingly affects us all in this era of “homeland security.” It’s a shame the two men never met — it would make for a very interesting night to listen to them talk over a few tequilas.

Mr. Rivard is the editor of the San Antonio Express-News. His book,”Trail of fathers: Searching for Philip True” (Public Affairs, NY) comes out this month in paperback.