More. Always there was more -- one more aide to question, one more letter to read, one more Lyndon Baines Johnson classmate to smoke out, one more library box to pry open.

Now Robert A. Caro, biographer of Johnson and chronicler of his power, is publishing "Master of the Senate," the third volume in his Johnson project, "The Years of Lyndon Johnson."

He plans one more volume. He has spent 26 years on this task, nearly as much time as Johnson spent in national power. He has riled much of an establishment of Democrats whose fires were lit by Kennedy and then set roaring by Johnson. Who is he to redefine the Johnson who defined them?

Caro, who is 66 now, has spent his whole middle age on Johnson, and if the past is a guide, he might need eight more good years, or even more, given the fact that he has yet to write about Johnson as vice president or president; about Johnson and Vietnam, the Kennedys, the Great Society -- the Johnson we remember more than any other, the Johnson whose immense hopes, passions, mistakes, despairs, accomplishments and legacies all seemed to bear the motto: "More."

Caro is a single-minded man with a large ego, an independent spirit and an obsession with power, a man who studies hard the men he admires.

Caro has knelt down and buried his hands in the shallow Texas topsoil to see what godforsaken odds the Johnsons were up against as farmers and ranchers; he has slept under the stars in the Texas Hill Country, eaten chicken-fried steak and dropped buckets down wells to see how heavy they were for Hill Country housewives. He has persuaded Sen. Bill Bradley to pose like Lyndon Johnson on the Senate floor because he wanted to see just how a man of his height would loom over his colleagues. He has risen at dawn to watch light dance on the Capitol the way the early-rising Johnson saw it.

He interviewed more than 260 people for this book, some several times, and dove into the 2,082 boxes of Senate papers in the Johnson Library in Austin. There's more to come.

Johnson Through Johnson's Eyes On a recent morning Caro is conducting a tour of Capitol Hill, standing on the Capitol steps, pointing out where Johnson once lived -- the site of the old Dodge Hotel near Union Station -- and roaming around the rotunda of the Russell Senate Office Building, gazing upward and outward at the past through his tortoiseshell bifocals.

Four-button blazer, blue shirt, red-and-blue tie, gray slacks, black shoes, dark thinning hair graying at the temples. Caro could pass for a legislative aide, a parliamentarian, a professor, the old Princetonian that he is.

Often he closes his eyes before he speaks.

A couple of folks in military uniform stroll by and Caro says, "See!"

See what?

Johnson was on the Armed Services Committee, Caro explains, and military people were coming to visit the senators back then the way they are today.

Seeing what Johnson saw. And passing that on to the reader. That is the Caro way. Caro says he has shied away from "getting into the mind of Johnson. I tried to show the things he saw, show them honestly enough. Then the reader may be able to understand him."

The first two installments, "The Path to Power" (1982) and "Means of Ascent" (1990), were both lauded and lambasted. Volume 1 told of Johnson's childhood and college years. The second chronicled Johnson's World War II experience through his campaign for the U.S. Senate, including assertions by Caro that Johnson grandly exaggerated his combat experience and stole the election of 1948. Each volume won a National Book Critics Circle Award as best nonfiction work of the year.

Of Volume 1, a reviewer in The Washington Post wrote, "Caro's evocation of the Texas Hill Country, his elaboration of Johnson's unsleeping ambition, his understanding of how politics actually works, are -- let it be said flat out -- at the summit of American historical writing."

Time magazine said of Volume 2 that certain scenes reached "poetic intensity."

Johnson loyalists, however, were not so generous. "He began with the preset view that LBJ was a monster," former Johnson aide Jack Valenti told The Washington Post in 1982. James Rowe, an FDR adviser who knew Johnson well, called "The Path to Power" a "hatchet job."

When Volume 2 came out, Newsweek quoted Johnson's right-hand man and former Texas governor John Connally -- and Caro source -- as saying that Caro "put an anti-Johnson spin on everything he could."

Volume 3, which charts the years that Johnson served in the Senate (1948-1960), is sure to draw new fire.

"Every book I write is controversial," Caro tells people.

With his eyes shut in the great round Russell Building foyer, he says, "When Johnson ran the Senate, there was only one office building. This one."

Not much hustle-bustle back then. "There were very few tourists," he says. "Very few constituents came in." He describes the building like it was a gentlemen's law firm.

"You didn't have groups of people like this." He points to a crowd of schoolchildren.

He gazes down one hallway where state and American flags grace office doors. "No one would think of putting flags out," he says, thinking of the past. "Tacky."

Walking across the floor, past a sad white statue of Sen. Richard Russell, Caro looks down another corridor. There is a window at the end. Faces of people coming toward Caro are in shadows.

Caro recalls standing in this spot at some time during the 12 years it took him to research and write the book. A man approached him using two canes. "For a moment, I thought it was Robert Taft."

It wasn't. Sen. Robert Taft of Ohio died in 1953.

Thinking With His Fingers Extraordinary that Robert Caro could be drawn to Lyndon Johnson, someone so different from himself.

Born in 1935 to a Polish father and an American mother, Caro grew up on Central Park West. His father, Benjamin, was a businessman.

When Benjamin died, Caro went looking for his father's date of birth to etch on his tombstone. "Almost every document I found had a different date," Caro says. He eventually took an average and chose that year -- 1890 -- to put on the stone.

Benjamin Caro didn't have much of a formal education. "He wouldn't talk about his life," Caro recalls.

He was a reader of newspapers and he wanted to become proficient in English. "When he was in his thirties he would copy out the New York Times," Caro says. "But he just wasn't interested in books."

Caro went to grade school at P.S. 93 and high school at the Horace Mann School.

In 1953 he entered Princeton, where he wrote for the campus daily. R.W. "Johnny" Apple Jr., associate editor of the New York Times today, was also on the staff. "We were a couple of extremely ambitious and aggressive young men and we competed for the editorship," Apple recalls. "I won."

Apple remembers Caro as being "just as dogged, just as single-minded, just as talented and just as humorless" then as now.

Caro assumed the title of managing editor. When Apple dropped out of college, a student named Eberhard Faber IV, scion of the pencil manufacturers of the same name, took over as the top editor. "Caro had a tremendous drive to be the best there was," Faber recalls. When he got hold of a story or an idea, "he was very hard to shake off."

Faber adds, "He was kind of a loner in those days."

While at Princeton, Caro fell under the spell of creative writing professor R. P. Blackmur, a white-haired and mustachioed man with a deep reverence for the transforming power of words.

"In my memory, we met every week for two hours, and every two weeks we had to turn in a short story," Caro says. When Caro was a senior, Blackmur called him into his office. First the teacher complimented the young writer on his descriptive abilities. Then he gave him the bad news.

Caro closes his eyes and recalls the words: If you don't stop thinking with your fingers, you're never going to achieve what you want to achieve.

"I didn't think," Caro admits. "It was easy for me. I was too facile."

After graduation, he married Ina Joan Sloshberg, who was still a student at Connecticut College. They have been married for 44 years and have one son. In a Central Park West accent, he pronounces her name "Iner."

A medieval historian, Ina Caro is the author of "The Road From the Past," a driving-tour history of France. She is also her husband's only researcher.

Just out of college, Caro turned down a copy boy job at the New York Times to become a reporter at the Daily Home News in New Brunswick, N.J. After a year and a half there he went to Newsday.

Caro's mentor and tormentor at Newsday was managing editor Alan Hathway, a bald guy who wore brown shirts and bright ties and admonished reporters to "turn every page" and "never assume a goddamn thing."

In a history of Newsday, Robert F. Keeler writes about the time that Caro, who was just a young grunt in the newsroom, filed a story memo to Hathway. The exacting editor summoned Caro into his office, and Caro thought he was going to be fired. Instead, Hathway said he had no idea that a kid from Princeton could write such a well-researched memo. He assigned Caro to investigative reporting.

"Once he attained that status," Keeler writes, "Caro was not always a popular figure in the newsroom. Some considered him a prima donna . . . But no one could deny that he brought to his work a high level of talent and a searing tenacity."

Another editor, Tony Insolia, remembers the way Caro covered news stories, such as murders and suicide attempts. He would work the phones, Insolia says. "He wanted to see the area where something happened, so he went out to see it. Nine out of 10 reporters would sit on their butts and not do anything. He wasn't looking for the easy way out."

Fellow reporter Bob Greene recalls, "He had that doggedness. I kind of liked that."

And "what got you about him in those days," Greene says, "was enormous energy. He had a very healthy ego, which is not necessarily sinful."

Greene says that many members of the staff used to congregate at a local watering hole, Leo's Midway in Garden City, to get paychecks cashed and wet a whistle or two. "Bob didn't hang out. He moved down his own stream," Greene says. "He just wasn't one of the boys."

"That's not true," says Caro with a historian's certainty. "Ina was always angry with me because I went to Leo's."

"You were very aware of the fact that he went to Princeton," recalls Newsday veteran Harvey Aronson. "He had his sports coats made by whatever the shop in Princeton was."

That's not true either, Caro says. "I've never had a suit made."

In 1965, he received a Neiman Fellowship. While auditing an urban and regional planning class at Harvard University, he decided that he knew more than the professor about why highways get built where they get built. At that moment, he decided to write a book about New York City construction superintendent Robert Moses, the man who determined where highways were built in New York City.

He started the book in 1967. He and Ina scraped by. They had a young child. Without telling her husband, Ina put their Roslyn, Long Island, house up for sale and they downshifted to the Bronx. "The Power Broker" was published in 1974. Caro won the Pulitzer Prize, and the financial clouds began to lift.

"My father," Caro says, "didn't understand why people would want to write stories about me."

Having explored urban political power, Caro wanted to look at national political power. He settled on the Senate. And "it was the Senate which attracted me to Johnson," Caro says. "He was the greatest majority leader in the history of the Senate. I took the guy who did it best. And studied him."

That's the way Francis Parkman -- Caro's hero -- would have done it.

Best known for his history of the Oregon Trail published in the 1840s, Parkman was an indefatigable researcher. "He insisted on seeing anything before he wrote about it," Caro says. He checked out battle scenes on horseback or in a canoe.

Somewhere among the persistence of Parkman, the literary vision of R.P. Blackmur and the check-it-out ethic of Alan Hathway, Caro was forged.

Get-Off-the-Couch History "I'm not a historian," says Caro, who still views himself as that reporter who insisted on seeing the crime scenes himself.

He loves to tell war stories of hunting down obscure papers and people in his search for more about the life of Johnson.

By stumbling on a list of congressmen and the amounts of money they wanted Johnson to cajole from Texas oil tycoons, he began to understand how Johnson put other politicians in his debt.

By talking to Johnson's chauffeur, Caro learned that Johnson often rehearsed what he was going to say to folks at the next destination.

By interviewing scores of people who had heard Johnson give speeches, Caro feels like he was better able to re-create Johnson's speech patterns and rhythms. Like newspapermen of yore, Caro doesn't record his interviews.

By temporarily moving to Washington and spending day after day in the Senate gallery, in committee rooms and in hangouts such as the cloakroom, Caro gained a deeper understanding of cloture, filibusters and how the Senate works.

Coupled with Caro's go-getter research techniques is an intense interest in writing well to suit the occasion.

If he's describing Johnson's desperation, for instance, he tries to make his own language sound desperate. "Words, adjectives have to be short," he says. "Desperation isn't long words; it's short words."

Like this scene of Johnson in the Senate cloakroom: "Often, while he was talking to one senator, a call he needed to take immediately would come in on another line. A clerk would tap timidly on the door of the booth in which Johnson was talking, and tell him that the other senator was ready. Stepping out of the booth, the telephone still in his hand, the cord stretching with him, Johnson would reach into the other booth and take that receiver, and then stand between the two booths, with the cords stretching out from them to his hands."

Caro says: "If it's not well written, it's not being faithful to history. Because history is not just facts, but the atmosphere, the sense of place, the drama of what occurred."

Because of his active, get-off-the-couch approach to history, Caro says, "academics really don't like me."

Stanley Kutler, professor emeritus of history and law at the University of Wisconsin, agrees that the differences between investigative reporting and historical reporting are blurry. "History is written with the long view in mind," he says. "That's not my problem with Caro."

Kutler's concern: "The book will sell oodles of copies. But 20 years from now it won't be used by scholars writing on Johnson."

Caro "can't abide power," Kutler says. "No matter what subject he writes about, he writes about power. It's the dirtiest four-letter word in Caro's vocabulary. He hates power."

Power is at the center of the new book. In more than 1,100 pages, Caro shows a sometimes cruel, sometimes compassionate, at times obsequious and always ambitious Johnson grabbing for prestige during his 12 years in the Senate and then wielding it to ensure the passage of the Civil Rights Act of 1957.

Power reveals, Caro says.

And Caro reveals. Just about everything. More than many people might want to know about Johnson.

The reader not only learns a lot about Johnson, and the Senate along the way, but also more and more about all sorts of legendary characters such as Sen. Richard Russell of Georgia and Rep. Sam Rayburn of Texas.

"The great quality of Bob is that everything is just as important as everything else," says Robert Gottlieb, Caro's longtime editor.

"I don't view my books as biographies," Caro says. He believes they are about the uses and misuses of power.

One early critic of the new book points out that Caro pretty much ignores the Republicans during Johnson's Senate years. Another says he relies too heavily on certain interviews that suit his purposes -- with Johnson aides Horace Busby and George Reedy, for instance -- and doesn't make use of many documentary records that are in the libraries.

In "Master," Caro writes: "Primary written sources are . . . not particularly helpful because of the nature of Senate life in the 1950s, in which so much crucial business -- negotiating, persuading, the fashioning of compromises -- was conducted not in writing but orally, face to face, or over the telephone, between the people involved, so that the only way to try to re-create the world of the Senate, and of Johnson's role in it, was to talk to these people."

His relationship with the LBJ Library has been strange and strained.

Harry Middleton, former director of the library, wrote in a 1983 newsletter to supporters of the Johnson Library that Caro had been unfair to Johnson, saying that Caro had "a loathing so deep it coats a steamy sheen over his prose." And "Caro seems to have set himself a goal breathtaking in its arrogance: He aspires to nothing less than to fix Johnson's image in history; he wants the man he has created to be the man people remember a century from now."

Middleton says now, "I came to regret that." And "I feel it was unprofessional."

He wrote to Caro and apologized.

Caro says: "Academic historians may think they are the only historians. But who writes the history people read?"

He goes on: "It's said that history is dying in this country. By some measures it is: You can graduate from college without taking a history course. Some colleges don't have departments of history."

But looked at another way, he says, history is very much alive. He points to the popularity of Edmund Morris, David McCullough, David Halberstam and himself.

Many of the bestselling historians do not have PhDs. "There's a reason for that," Caro says. Academic historians often don't understand that "the writing matters as much as the facts."

At the recent annual gathering of the Organization of American Historians, Caro uttered this passionate but skew-phrased pronouncement, "Writing matters everything."

Looking at Mount Everest And reading matters everything. Since finishing the book, Caro has been rereading Anthony Trollope. "He is the best writer on politics," Caro says.

He's thinking about his next book, the fourth and final volume on Johnson -- an examination of the vice presidency and the presidency. "It's one story," he says, "bracketed by the Kennedys."

Simply put, Caro says the two sides of Johnson's presidency -- Vietnam and social welfare -- reflect Johnson's dark side and bright side.

He's working on the outline, which he pins to the eight-yard-long wall of his office, just off Columbus Circle. In the margins he scribbles notes to himself: "Don't sound like a schmuck." "Is there desperation on this page?"

He writes first in longhand on a legal pad -- to slow down his fingers -- and then on a typewriter, a Smith Corona Electra 210. The company no longer makes that model, so he has stockpiled 14 others to cannibalize for parts.

Sometimes after a long day, Caro runs four miles or so through Central Park to his home on Central Park West. While he jogs, he works on the outline.

Lewis L. Gould, professor emeritus of history at the University of Texas, says, "The problem he's got for himself is he's in his sixties and he's standing at the foot of Mount Everest."

Caro works slowly. He worries he might not live long enough to finish the Johnson biography.

"I know a lot of stuff no one else knows," he says.

At the same time he has hopes for future projects unrelated to Johnson.

So what drives Caro?

"A sense of injustice," says Ina Caro.

"Consuming interest, unending curiosity, getting everything right, the temperament of an obsessive worker and accomplisher," says Gottlieb.

Is he softening toward Johnson? No, Caro says. "In this book he finally gets power. One of the things that is revealed is his compassion."

He adds, "But it's the same character. The man hasn't changed."

"I think that this is what was always going to happen," Gottlieb says. "Bob started out with no judgment of Johnson. He admired him. When he began to explore Johnson's youth and ascent to power, I think he was distressed and shocked by a lot of what he discovered."

With the new book, "he's got to that part of Lyndon Johnson that he always admired," says Gottlieb.

And how is Caro different from other writers Gottlieb has worked with? "He's probably just more."

More what? "More compulsive," Gottlieb says. "More devoted. More focused."

"History is not just facts, but the atmosphere, the sense of place, the drama of what occurred," says award-winning biographer Robert Caro."It was the Senate which attracted me to Johnson. He was the greatest majority leader in the history of the Senate," says his biographer, Robert Caro. "I took the guy who did it best."