The Years of Lyndon Johnson By Robert A. Caro

Knopf. 506 pp. $24.95

WITH THIS second installment of his monumental biography of Lyndon B. Johnson, author Robert A. Caro has dug himself far deeper into a Texas-size hole. The caricature of Johnson as Evil Incarnate that was sketched in the 1983 volume covering the first 33 years of his life here becomes a Daumier-deep etching. It's hard to imagine how Caro is going to explain in subsequent installments the achievements Johnson recorded as Senate majority leader and president or the knowing risks he took in his last 20 years of growing power.

After the biographer has labored so mightily to convince readers that the man is utterly selfish, self-aggrandizing and unscrupulous, he will have to ask them either to erase that image from their memories or convince them that the man who put his party at risk for the cause of civil rights and who put aside the presidency in acknowledgment of his failure in Vietnam was somehow transformed from the slimy creature who stole the 1948 Texas Senate election.

The Lyndon Johnson that emerges from this book is a complete scoundrel in both his personal and political life. He abused his associates and betrayed his wife. Driven by "a boundless ambition . . . his career had been a story of manipulation, deceit and ruthlessness . . . From the earliest beginnings of Lyndon Johnson's political life . . . his tactics had consistently revealed a pragmatism and a cynicism that had no discernible limits. His morality was the morality of the ballot box, a morality in which nothing matters but victory and any maneuver that leads to victory is justified, a morality that was amorality."

At times, Caro seems almost apologetic for what he's done. In the introduction to this volume, he writes that two threads -- one bright, the other dark -- "run side by side through most of Lyndon Johnson's life" -- but not in this book. "The bright one is missing. For this volume is about a seven-year period in the life of Lyndon Johnson . . . in which Johnson was all but totally consumed by his need for power, and by his efforts to obtain it."

The story begins after the 1941 Senate race, in which Johnson was defeated -- Caro argued in Volume I, it was more a case of being out-stolen -- and sent back to the unendurable obscurity of the House of Representatives.

This volume centers on three events: his brief wartime service, his acquisition of wealth through an Austin broadcasting station and the 1948 election in which he came to the Senate. In every one of the three, Johnson is depicted as a lying, cunning, utterly unprincipled operator.

Caro, the researcher, assembles a formidable mass of evidence to support the charges. Caro, the writer, tells each tale with energy and relish, emphasizing the damning incidents through repetition and sliding the unwary reader past the points in the narrative that might raise doubts about Caro's interpretation.

If the author trusted his readers enough to let them make their own judgments, if he permitted them to grapple with the complexity of character of one of the most fascinating politicians of this century, he would have written one of the great books of our time. By tilting the tables to make crystal-clear the personal abhorrence he has come to feel for his subject, he strains credulity.

I think Caro makes a persuasive case that Johnson manipulated and exaggerated his wartime military experience, used his political connections to obtain and to develop radio station KTBC in Austin and stole the victory in the 1948 Senate race. That would be enough to satisfy most investigative reporters or expose-minded authors. But Caro wants to write a morality tale, an epic of democracy betrayed -- and his ambition betrays him as surely as Johnson's conceit about bringing "one-man-one-vote democracy" to South Vietnam undermined him.

Of the three central topics, Caro is probably most balanced and persuasive in telling the sometimes hilarious, always hypocritical story of Johnson's military service. Trapped by a rash 1941 campaign promise never to "vote for war and then hide behind a Senate seat where the bullets cannot reach me," Johnson finagled himself a brief observer's trip, in Navy uniform, to the South Pacific. Caro concedes that he performed valorously on his one combat mission, but accurately ridicules the later exaggerations of Johnson's wartime tales.

Caro sorts through the tangled story of the negotiations that gave Lyndon and Lady Bird Johnson control of KTBC and the way in which he used his Washington connections to boost its power, lengthen its broadcast day and gain it a network affiliation -- thus multiplying its value.

But even in these two areas, he pushes his argument beyond the level of credibility. He cannot resist a sarcastic comment here, an unprovable assumption there. His sketch of Johnson recruiting a business manager is so true-to-life it makes you whistle, but his insistence that Johnson had such a "loyalty" fetish that he only employed hacks is utterly false -- a total distortion of Johnson's lifelong history of surrounding himself with people of exceptional skill.

It is in the 1948 campaign chapters that Caro's determination to reduce everything to a black-and-white morality tale reveals itself most clearly and disastrously. That campaign was an American classic, in which Johnson battled against severe health problems, an adverse political climate and a strongly favored opponent to win by the narrowest of margins -- the 87-vote victory that earned him the derisive nickname of "Landslide Lyndon." And then, after the votes were counted, Johnson went through an equally breathless battle in the state convention and the courts to make his clearly tainted victory stand up.

It's a story that needs no hyping, but Caro isn't satisfied just to uncover and recount how one politician outfoxed another. Instead, he makes Johnson's opponent, Coke Stevenson, a saintly figure of surpassing virtue and innocence, ravaged by the Predator of the Perdenales.

There was something of this in the first volume, when Caro sought to strip Sam Rayburn of the wiliness that made him such a great Speaker of the House in order to portray him as the hapless victim of Johnson's favor-seeking with FDR. But with Coke Stevenson, he pulls out all the stops -- and distorts history in a way no serious biographer should do.

As Johnson hopped around Texas in a helicopter -- a campaign innovation Caro describes in loving detail -- he ridiculed his rather stuffy opponent for endlessly repeating, "Ah believe in constitutional government."

"These savage personal onslaughts," Caro writes, "were directed against perhaps the most respected public official in the history of Texas." Really? Texans to whom I have quoted that line are inclined to hoot. Stevenson was a popular, honest governor but one who left little of a mark on the politics or government of his state. One thing for which he is remembered was fleeing the capitol when students and faculty marched in protest against the firing of University of Texas president Homer Rainey in one of the celebrated academic freedom cases of the '40s. Caro says only that "Stevenson's refusal to intervene in this controversy revealed that he did not adequately grasp that concept {academic freedom}."

Another thing that is noted about Stevenson in standard histories of Texas was his refusal to respond to petitions from legislators to call a special wartime session to relieve Texas servicemen from paying the poll tax. Caro doesn't mention that. Nor does he mention Stevenson's heavy stress in the Senate campaign on his opposition to foreign aid -- an important issue when Congress and the country were debating the Marshall Plan. Horace Busby, the Johnson aide Caro quotes accurately in several disparaging anecdotes about his subject, tells me that he told Caro that these matters were critical in rallying support for Johnson among young veterans and their families. But in all the 200 pages on the campaign, he never mentions that element in the election.

It is hard to avoid thinking that these omissions are deliberate, that they are tailored to the sensibilities of those who have lapped up the serialization of Caro's book in the pages of The New Yorker as definitive proof that the president who "got us into Vietnam" had always been a scoundrel. Had they been told that in 1948 Johnson was running against a right-wing isolationist who'd permitted Red-baiters to run off one of his state's most respected intellectuals, they might not have worked up the degree of disdain for Johnson Caro wanted to produce.

The 1948 campaign story is eminently worth reading. But how much better it would have been had Caro not distorted the central characters. Sure, Johnson was capable of buying votes in the Valley counties where they were for sale. But does Caro seriously intend us to believe that when those same bosses gave the same inflated margins to Stevenson in his earlier races, it was "not for the traditional reasons"? Is he an historian or a propagandist for a long-lost cause when he writes, "Money was never a factor in the Valley's support of Stevenson -- he treated the jefes with the same indifference and independence that he displayed toward other powerful political figures"? Give me a break.

The distortions become all but fatal to the reader's understanding when Caro undertakes to persuade that Johnson sold out to the Texas right-wing in his lust for victory. If that were true, the support that backers of President Truman gave Johnson at the state convention -- when he was fighting to have his stolen victory certified -- made no sense. But that backing from the Truman forces, who were battling the states-rights, segregationist Democrats aligned with Stevenson, was critical to Johnson's success. And so Caro's description of the convention dealing appears far less plausible than in fact it was.

These are serious flaws in a volume that is largely Texas-centered. The next books will deal with Johnson as a growing Washington and national figure. And I fear that Caro's inability to recognize that all politicians are mixtures of noble and ignoble traits, not classifiable as skunks or saints, may fatally undermine what might otherwise be an epochal achievement.

David S. Broder, the national political reporter for The Washington Post and a syndicated columnist, is the author, most recently, of "Changing of the Guard: Power and Leadership in America."