L.B.J.’s Dark Years : Biography: In his second volume on the former President, author Robert Caro takes a bleak view of Lyndon Johnson’s life from 1941 to 1948 .

Everything about Lyndon Baines Johnson was outsized. His physical bulk, his energy, his ambition, his tirades, his deceptions and even his ears made Johnson a political mega-force.

No less forceful is the work of Robert Caro. The former newspaper reporter has labored for 14 years to turn the life of Johnson into what will be a four-volume biography that, he says, will tell the darkness-and-light tale of how a poor boy from the lonely Hill Country of Texas acquired power in Congress, became a millionaire, clawed his way to the U.S. Senate in a “stolen” election, ascended with alacrity to become Senate Majority Leader and twisted arms as President to turn his civil rights initiatives into law.

Caro’s L.B.J. in the newly published second volume, “Means of Ascent” (Alfred A. Knopf), is unrelentingly dark. There is none of the Johnson-as-the-boy-wonder depicted in the first volume, the young congressman who brought electricity to the 200,000 farmers and ranchers of his rural district.

The L.B.J. in “Means of Ascent” angrily stalks through the bleakest wilderness of his life.

But, like Johnson, the second volume of Caro’s opus is ambitious and compelling. Even Horace Busby, a longtime Johnson adviser, who disagrees with Caro’s savage evocation of the period, says: “My feeling is he’s making the man a legend. Carl Sandburg would have to write another book about Lincoln to keep up with Caro.”

Knopf has dispatched 250,000 copies of “Means of Ascent” across the country, up from the original 200,000 first printing. The book is a main selection of the Book-of-the-Month-Club and six excerpts of it have appeared in the New Yorker.

Caro has spent seven years on each of his books: “Means of Ascent,” “The Path to Power,” which earned Caro the National Book Critics Circle award for nonfiction and “The Power Broker,” Caro’s Pulitzer Prize-winning biography of New York’s master-builder, Robert Moses. He has also spent part of the past 14 years on a novel about the newspaper business, which he left in 1967. All he will say of it is that “it is immense.”

Working with his wife, Ina, a medieval historian and his research assistant, Caro has spent months at a time in Texas, reading some of the 34 million papers in the Johnson Library in Austin and driving rented cars thousands of miles across the state for interviews.

If possible, Caro wants to be where Johnson was, to visualize what molded his subject, much as Francis Parkman, the historian Caro admires most, did when writing about the American Indians.

When Caro didn’t comprehend Johnson’s upbringing in the lonely Hill Country and residents didn’t trust that the city boy with the New York accent was committed to knowing them, he and Ina moved near them for parts of three years. He gained their trust and their unembellished memories.

When he wanted to understand the area’s loneliness, he took a sleeping bag and camped out on a ranch for four days, waiting as Lyndon and his brother, Sam, once waited for a car to come by so they’d have somebody to talk to.

In 14 years of studying his subject at the Johnson Library, 787 document boxes filled with notes, memoranda, letters, telephone transcripts and speeches--altogether about 629,000 pages of documents, have been delivered to Caro in the eighth-floor research room.

Caro says he has dug deeper and wider than any biographer (there have been 21 others) to understand Johnson. “Everything in this book,” Caro says, “is true and documented beyond the possibility of any doubt. That’s just the way it is.”

What Caro covers in “Means of Ascent” is a seven-year period in Johnson’s life, from 1941 to 1948, when the future President saw his way blocked to power in the House of Representatives and election to the Senate. He had lost a special 1941 Senate election and reluctantly stayed out of the 1942 race, to follow through on a promise to fight in “the trenches” if war brought out.

He was no longer the pet of House Speaker Sam Rayburn or a President’s southern protege after Franklin Roosevelt’s death in 1945. He craved influence and money, but had neither. As he eyed the 1948 Senate election, Caro writes, it was “all or nothing.” If Johnson lost, he’d return to a life he dreaded, to being ordinary and poor, like his daddy.

The Johnson of Caro’s uncompromising portrait of these years “is unrelieved by redeeming social values,” says Robert Gottlieb, the editor of the New Yorker, who has edited all of Caro’s books for Knopf.

It is not a picture corroborated by Johnson confidants like John Connally and Horace Busby--who admit they can’t fault Caro’s reporting, just his conclusions. Connally, former governor of Texas and secretary of the treasury, says: “For whatever reason, Caro has painted the dark side of Johnson without the benefit of the doubt on anything. Why I don’t know. But the problem in arguing with Caro is it’s impossible to dispute his facts. I don’t argue the facts, but the nuances and interpretation.”

Caro shakes his head at Connally’s remarks. Connally refused to speak to Caro until two years after the publication of “The Path to Power.” Says Caro: “My interviews with him were four days of the most fascinating interviews I’ve ever had. When we started talking, he was enthusiastic about the book. But since he started his own book, that enthusiasm has lessened. He told me the reason he talked to me was because I had gotten Johnson ‘right on the head’ and he didn’t want me to write any more volumes without him.”

Says Busby: “I’m not detracting from his work, but Johnson was a many-sided man who was difficult to capture. Caro doesn’t deal with the extreme sensitivity of the man, and I was closer to that side of him than anybody else.”

From the start of his work, Caro’s goal has been to separate legend from truth by speaking to people never interviewed before and pressing others to reconstruct events as they happened. Among the parts of the Johnson legend Caro disassembles:

* Johnson’s war service. After a desultory 10 weeks of inspecting shipyards for the Navy, a period enlivened only by parties and practical jokes, and after Roosevelt rebuffed him for high-level Washington desk jobs, Roosevelt sent Johnson to the Southwest Pacific to survey the war effort. While Johnson maintained that he played an important combat role, he was only an observer on a bomber that saw 13 minutes of action against Japanese Zero fighters. Gen. Douglas MacArthur awarded him the Silver Star. Back home, L.B.J. had the Silver Star pinned on him at public appearances, and became the increasingly heroic “Raider” Johnson.

* Johnson’s wealth. As President, Johnson maintained that the broadcasting empire that started with buying the KTBC radio station in Austin in 1943 was built by Lady Bird. He had nothing to do with it. But Caro shows that it was Johnson’s influence with the FCC that helped buy the station, change it to full-day operation and shift it to a better frequency. It was Lyndon who won a CBS radio affiliation for KTBC, unavailable to a rival Austin station. It was Lyndon to whom influence-seeking local lawyers and businessmen came with open pockets to advertise.

Caro intended “Means of Ascent” to carry Johnson up to John F. Kennedy’s assassination in 1963, but he stopped in 1948, the year of Johnson’s “stolen” victory in a Senate primary runoff.

The primary campaign matched Johnson, running as if for his life, and Coke Stevenson, the stoic former three-term governor who never made promises or presented a campaign platform. Stevenson won the primary by 71,000 votes, but it wasn’t enough to avoid a run-off.

What happened next is why material that began as one chapter turned into two-thirds of Caro’s book.

“If I showed the 1948 campaign in depth, I could show things I’ve always wanted to show about American politics,” says Caro. “I could show the full destructiveness of the new media politics on the political process. In Coke Stevenson, you had the old politics in a pure example. It was the end of an era; no one ever campaigned like this again in Texas. And here is Lyndon Johnson with his new politics and media manipulation. He didn’t create the new politics, but he brought it to a new maturity.”

That the run-off was stolen is not disputed. But Caro disproves the myth that the votes filched in Johnson’s name represented business as usual in Texas politics and that everybody did it--even Coke Stevenson. Caro found that no race had ever witnessed a vote theft so massive, where thousands of votes shifted to Johnson for six days after balloting closed. Johnson’s puny 87-vote margin of victory was contrived when the corrupt Rio Grande Valley political boss, George Parr, ordered Luis Salas, an election judge in Jim Wells County, to add 200 votes for Johnson. “If the votes were not for Johnson, “I make them for Johnson,” Salas later said.

Caro does not say Johnson directed the vote thefts. But he does not believe denials that L.B.J. lacked personal knowledge of what was being done in his name.

“For 40 years, people didn’t know what happened,” says Caro, “and I said I wasn’t going to write a biography of Lyndon Johnson where in the pivotal point in his career, I’m not going to know the truth.”

But it was not the election that tantalized Caro as much as Coke Stevenson, the symbol of the end of the old ways. In Stevenson, Caro found the perfect antithesis to Johnson.

Caro wasn’t prepared for Stevenson; he had barely heard of him until people who knew Johnson told stories of the cowboy governor’s honesty. In the capital of Austin, Stevenson was known as the man who could not be bought.

Throughout the 1948 campaign, Johnson lied about Stevenson’s positions; he insulted, mocked and aped him. Repetition was the key. But Stevenson wouldn’t reply. Johnson’s new politics trampled Stevenson’s old politics. Unlimited cash let Johnson pound his message over the radio airwaves. Stevenson campaigned simply, driving into towns, giving speeches on courthouse steps.

Connally says Caro “beatified” Stevenson to set up Johnson as “the man in the black hat. There was no balance at all. Stevenson was an old-style politician who was well-regarded; he sure wasn’t all that beloved.”

“He didn’t say anything about Stevenson’s integrity, did he?” asks Caro. No. Caro nods, certain as ever, of the rightness of his portrait.

Caro writes in an office on West 57th Street, not far from the apartment he and Ina, who were married 32 years ago, share on Central Park West. His workplace is spare: a stained white couch, dirty walls, unwashed windows, scratched wood bookcases, used file cabinets and a shabby desk.

He arrives each morning about 8, but when thoughts rouse him from his sleep, he’ll be at his desk before sunrise. He hates distractions; when he writes, he shuts off the telephone and answering machine. The mail slot on his door is blocked with a steel plate.

He is an exacting perfectionist who doesn’t think he’s taking too much time to study Johnson and who believes that the truth takes time. He wonders why, after he’s set down all the facts, people could disagree with him.

“I believe that while someone may quibble with me,” he says, “they’d be wrong.”

For all his intensity and what Gottlieb calls “his free-floating anxiety,” Caro is unfailingly polite and respectful. It’s not difficult to visualize how Caro induces Johnson friends and intimates like lawyer Ed Clark, a Texas power for 40 years, and contractor George Brown of Brown & Root, which helped bankroll Johnson’s campaigns--men who had never talked to biographers or whom other biographers ignored--to open up.

“My models for interviewing are George Smiley and George Simenon’s Inspector Maigrit,” says Caro. “What distinguishes both is their empathy, how they understand what they’re hearing rather than ask a lot of questions. I’m always writing ‘shut up’ to myself in the note pad.”

One Caro technique is to take interviewees back to key places to help them recall important moments in Johnson’s life. In Volume One, he took Lyndon’s brother, Sam Houston Johnson, back to the family home to re-create the searing arguments between Lyndon and their father.

Caro almost always refuses to use a tape recorder, except for rare technical interviews. A wooden cabinet in his office stores precisely stacked piles of pads, each annotated on the cover with the people interviewed.

Many more notebooks will be filled before Caro is done. He is now writing about Johnson’s Senate years in Volume Three, covering the period when Johnson became the most powerful majority leader in history. This time, threads of dark and light run together, as Johnson uses questionable means to pass early civil rights legislation.

“His personality doesn’t change,” says Caro. “All the old traits, good and bad are there, but he’s using them in a noble cause. To watch him tirelessly maneuver the civil rights legislation with his savage energy is fascinating.

“If I portray him right,” adds Caro, sitting on the edge of his couch, excitedly describing the work that lies before him, “we will never have to ask again what one aspect of political genius is. This is it. That’s why I raise the relationship between ends and means. By the time you finish my four volumes, anyone who wants to talk about the relationship between ends and means will have the material.”

Caro has been observing Senate action from its overhead gallery and examining papers, memos, letters and telephone transcripts of Johnson’s contemporaries. Caro says the most revealing information comes from the papers of lesser-known senators. “The story of how he came to power has never been told,” he says, “because some of the collections have never been looked at.”

Caro is bluntly confident that he will come closer than any biographer to knowing the man who could muscle into law both the Gulf of Tonkin Resolution and the Voting Rights Act.

One person who disagrees with Caro’s self-assurance is UCLA history professor Robert Dallek. He says that he’s done the historical research that will yield a more accurate portrait of Johnson, which he will publish in two volumes, the first to be published late this year.

“Caro is a muckraking investigative journalist who does a lot of interviewing, and he’s painted a portrait of saints and sinners, with elements of cartoon and caricature,” he says. “I’ve done interviews, but mine is based on 116 manuscript collections. My books rest on the contemporary record more than the memories of people about events from 30 or 50 years ago.”

Does Robert Caro hate Lyndon Johnson? No, says Caro. “Means of Ascent’ was meant to be dark, but it is only seven years. Lyndon Johnson is not the sum of his actions between 1941 and 1948. His positive impulses, manifested in rural electrification in the 1930s and social justice legislation of the 1960s, did not emerge in this period.

“We have to know this personality,” says Caro. “It may be unpleasant to know. His presidency was a watershed in American history. The country changed. In a watershed, on the top of a divide; waters on one side run in one direction and on the other side, they run in the other direction. That was Lyndon Johnson’s presidency. It wasn’t solely because of his personality, but if you have a long list of factors why history changed during his presidency, the personality of this President has an unusually heavy weight in the equation. You have to understand that.”