Take a biographer already trailing clouds of controversy. Have him write the third volume of a monumental work about an American president seemingly destined to be loved and hated for reasons as conflicted as the author and his subject. And what you get is a donnybrook in the book-reviewing fraternity that often reveals as much about the reviewer as the book.

Such has been the case about the nonfiction event of the year, Robert L. Caro's The Years of Lyndon Johnson: Master of the Senate. Like his previous two volumes on Johnson's early years and his disputed election to the Senate, Caro's tale of LBJ's relentless ability to ram through the first civil rights bill since Reconstruction has been extravagantly damned and praised.

But with a difference. Praise for earlier volumes, which won National Book Awards, has been obscured by the subsequent attacks of Johnson acolytes who remain convinced that Caro is always intent on demonizing their hero. The likes of Liz Carpenter and Bill Moyers won't even speak to Caro. Harry Middleton, director of the LBJ Presidential Library in Texas, once wrote in his newsletter of Caro's "hatred of his subject, a loathing so deep it casts a sheen over his prose."

So with the publication last spring of Caro's massive book on Johnson's Senate career, the stage was set for a hostile reception by those convinced Caro was always full of loathing. Yet Caro sees it otherwise. In an interview with National Public Radio he said of Johnson: "I don't either like or dislike him. I try to understand him. If you have a feeling towards Lyndon Johnson, it's awe."

Now Webster's defines "awe" as "a mixed feeling of reverence, fear and wonder," and until a better description of Caro's attitude toward Johnson comes along, critics ought to take him at his word.

Even in his first and most caustic volume, in which he traces Johnson's manipulative political skills back to a fixed election in college, Caro wrote with awe about the future president's hard years picking cotton and working roads under a harsh Hill Country sun. It was an experience as epic and as unlikely a preparation for the White House as Abe's rail splitting or Harry Truman's dirt farming. Caro has always been as full of wonder over Johnson's ferocious ambition as he has been of fear (or loathing?) for his crude, deceitful treatment.

With this as a background, the reviews that greeted Caro's newest work were as interesting for their comments about the biographer as the biographee. Detractors were in joyful pursuit of Caro's shortcomings -- his obsession with Johnson's barnyard behavior, his penchant for dramatic overkill, his neglect of benign Johnson actions outside the chosen field of civil rights; supporters dared to extol the author for his storytelling flair, his indefatigable research and his willingness to give Johnson his due as the greatest champion of citizens of color since Lincoln.

Among the latter, it must be said, there was often a bit of gushiness, a bit of dazzle. Especially among the British reviewers. In the New Statesman, Stephen Pollard found it "the finest biography I have ever read or could imagine reading. Caro is so much in command of his research and has so much to say that not a word is wasted."(This in a blockbuster book of 1,167 pages.)

Richard Lambert in the Financial Times wrote that Volume III of The Years of Lyndon Johnson has "all the breadth, color and pace of its predecessors" and suggested that "time has mellowed Caro" in his judgments of LBJ. (Here, again, emerges the notion that Caro was incessantly negative in his first two volumes.)

On this side of the Atlantic, The New York Times Book Review reflected some of Lambert's approach when writer Jill Abramson said Caro "has at last found something about his subject to unabashedly admire" -- Johnson's decision to join the civil rights cause. She unabashedly praised the book for Caro's "majestic storytelling ability," his "vivid, revelatory institutional history," his "rich hologram of Johnson's character."

Business Week's reviewer, Richard S. Dunham, described Caro as "America's greatest living presidential biographer." "With due deference to David McCullough," he wrote, "no other contemporary biographer offers such a complex picture of the forces driving an American politician, or populates his work with such vividly drawn characters." But he added, Harry Middleton style, that "Caro's Johnson-loathing gets annoying."

Among more critical reviewers, none was more assiduous in pushing the loathing mantra than Ronald Steel in The Atlantic Monthly. Himself the author of a hatchet-job biography on Bobby Kennedy, LBJ's nemesis, Steel saw another hatchet job in Caro's "long and ferocious struggle with his subject."

"Caro is the kind of moralist who is more concerned with the purity of a politician's heart than with the effectiveness of his actions," Steel contended, adding: "For Caro, ambition carries the stench of power, and no word in the lexicon disturbs him more. He is both fascinated by power and repelled by those who exercise it." He complained that Caro is so focused on Johnson's ambition that he loses sight of him as a human being. Example: If Johnson was so beastly to his wife, why was Lady Bird so devoted to him? "Only through what might be called literary empathy can a biographer show us why a person behaved a certain way," Steel lectured.

While Steel scored Caro for not depicting Johnson as a believing liberal, Arthur Herman in the conservative National Review took the contrary position that Caro was part of an effort by liberals to embrace a president they had often scorned. "As with most liberals, everything and everyone has to be fitted into a simple-minded dramatic scheme of heroes, villains and victims."

"The only standards Caro attempts to apply to the actions of others are his own," Herman continued. "This turns history into a moral minefield, in which the Good Guys in one chapter are instantly transformed into Bad Guys in the next, depending on whether they happen to support a progressive cause or oppose one."

A less partisan elaboration of this theme was offered by Nicholas Lemann, currently The New Yorker's man in Washington. Writing in The New Republic, he contended that Caro fails to "provide a coherent standard for judging politicians."

"What is this 'power' that Johnson craves?" Lemann asked. "Caro gets himself off the hook of having to define it by extravagantly admiring the accomplishment of any item that is on the liberal agenda -- any item that serves the cause of 'social justice' -- and treating all other signs of political adeptness as base and ignoble. The result of this back-and-forthing, depending on who is playing politics and to what end, leads to an overall confusion about Caro's operative code of conduct. Politics, of course, is a blend of morality and practicality, but Caro does not convey a clear sense of what he considers the proper mix to be."

Robert Caro, described by Lemann as "larger than life" within his reference group, has promised his fourth and final volume of The Years of Lyndon Johnson in five or six years. It will cover LBJ's vice presidency (probably in brief fashion) and his presidency (in great detail). If he sticks to form, his book will be controversial and conflicted, as will its reviews. What a delicious prospect!

Joseph R. L. Sterne is a senior fellow at the Johns Hopkins Institute for Policy Studies and was The Sun's editorial page editor from 1972 to 1997.