Biographers have been struggling to take Mencken’s measure since the 1920s. Fred Hobson’s Mencken (650 pages. Random House. $35) is the latest and best attempt. Hobson is the first of Mencken’s biographers to use all the posthumously published diaries, where the “Sage of Baltimore” vented his most odious bigotries and where he most clearly revealed the alienation and loneliness at the heart of his personality. Hobson does not try to resolve the contradictions in Mencken’s personality. Instead, he wisely uses this new material to portray Mencken as a man forever in conflict with himself, the carefree cutup coexisting with the control freak, the comic with the tragedian. Eventually-at least a decade before the 1948 stroke that robbed him of the ability to read or write-Mencken’s darker angels took charge of his soul. In 1942, he wrote, “I have spent all of my 62 years here, but I still find it impossible to fit myself into the accepted patterns of American life and thought. After all these years, I remain a foreigner.”

But as Hobson points out, the darkness was there all along, and the miracle is that out of this almost paralyzing bleakness, Mencken was once able to spin exuberant, lacerating prose that is as funny as it is essentially serious. At the peak of his powers, in the ’20s and early ’30s, he slaughtered every sacred cow in sight, from Prohibition to fundamentalism. But as hard as he could be on hillbillies and Klansmen, be was even harder on professors: “Of a thousand head of such dull drudges not ten, with their doctors’ dissertations behind them, ever contribute so much as a flyspeck to the sum of human knowledge.” Coining phrases like “the Bible belt” and aphorisms like “Democracy is the theory that the common people know what they want, and deserve to get it good and hard,” Mencken left his indecorous fingerprints all over American thought and speech.

As a newspaper columnist, a magazine editor and a book writer, Mencken radically broadened the scope and raised the standards of American journalism. But most important, he proved that an intellectual could thrive in the popular press. Reading Michael Wreszin’s new biography of Dwight Macdonald, A Rebel in Defense of Tradition (590 pages. Basic. $30), one is struck by the thought that had there been no Mencken, there might well have been no Macdonald. Macdonald himself acknowledged the debt in his famous attack on American mass culture, “Against the American Grain.” And the very shape of Macdonald’s career owes everything to Mencken’s example. A freewheeling critic of politics and culture, first in intellectual journals like Partisan Review, Politics and later at The New Yorker and Esquire, Macdonald (1906-1982) was the archfoe of middlebrow and lowbrow taste. In his legendary attacks on the third edition of Webster’s New International Dictionary and the Revised Standard Version of the Bible, he argued that debasing the language debased the culture; he wonderfully echoed the Mencken style. To clinch the comparison, Macdonald is most like Mencken in the way he is memorable even when he is wrong. Writing about Orson Welles’s “Mr. Arkadin” and “Touch of Evil,” he accused the filmmaker of letting “himself go, like an over-weight matron indulging in desserts, in melodramas which seem to have been whipped up entirely for theatrical effect.”

Murray Kempton proves himself an even closer student of Mencken’s method in his latest collection of newspaper and magazine work, Rebellions, Perversities, and Main Events (570 pages. Times. $27.50). Like Mencken, the 76-year-old New York Newsday columnist is first and last a newspaper man right down to the his shoes. Skeptical and well-worn soles of curious, he is equally at home writing about Dwight Eisenhower, the gangster Matthew Ianniello or the physicist J. Robert Oppenheimer, and he condescends to no one. With Mencken he shares a reflexive sympathy for the underdog, a distaste for cant and an addiction to thickety prose. Praising the singer Bessie Smith, he says, “We would still have no more used for her any name except the bare and stately ‘Bessie’ than we would have spoken of Juno as Mrs. Jupiter. Goddesses do not have last names.”

But the sad fact is, Mencken’s disciples are not Mencken. Flaws and all, he was inimitable. As Hobson says, “He was our nay-saying Whitman, and … he sounded his own barbaric yawp over the roofs of the timid and the fearful, the contented and the smug.” With his cheap cigars and his hick’s haircut, and with his gaudy, orotund prose, he looks and sounds like an old-fashioned vaudevillian-W C. Fields pounding a typewriter. As nice as it would be to stick this curmudgeonly, politically incorrect relic on a back shelf and forget about him, we need his rancor too much. Better than anyone, he still instructs us on the value of the loyal opposition. At his best, he made his readers think and he kept them honest. No journalist could want a better epitaph.