Biography is a merciless unmasker. Leon Edel, Henry James’s biographer, slightly altered one of the master’s phrases in declaring that the biographer uncovers the “figure under the carpet.” The Edelian biographer probes the subject’s private life and unveils unconscious – or at least unspoken – impulses.

The unconscious infiltrated 20th-century art. Eugene O’Neill, for example, employed masks in “The Great God Brown” and “Strange Interlude” in order to emphasize the divided self. But does this Freudian fuss about the fractured self apply to every case? Can biography in some instances do without this psychologizing – as Groucho Marx does in “Coconuts”? “Pardon me,” he announces, “while I have a strange interlude.” Groucho refuses to split himself in two: He always mugs for the camera in the same way with his painted-on mustache. No matter what character he is playing, he is always Groucho.

And so it was with William Jennings Bryan, a.k.a. “the Great Commoner,” standard-bearer of the working class, three-time Democratic Party presidential nominee (1896, 1900, 1908), scourge of corporations, nemesis of Wall Street, and in popular lore, the fundamentalist whom Clarence Darrow humiliated during the Scopes Monkey Trial.

Michael Kazin’s cogently argued new biography (Alfred A. Knopf, 400 pages, $30) destroys the caricature of Bryan the religious zealot and naive Democrat even as it shows Bryan the man and the orator taking on a stature that makes him a precursor of the New Deal (many of Bryan’s colleagues and followers gravitated to Roosevelt after their leader died).

Any biographer looking for discrepancies between Bryan’s private and public behaviors will be sorely disappointed. Bryan made lots of money from speaking engagements but never invested in the stock market. A charismatic politician and preacher, he turned away adoring women and not only remained faithful to his wife but was downright uxorious.

Bryan loved to lecture about Jesus Christ, and there was a good deal about him that was Christlike. Among the best features of Mr. Kazin’s biography are his quotations from letters written to Bryan – by the poor and downtrodden and by wealthy businessmen. People of all classes saw him as a kind of savior.

Bryan was not a fundamentalist in the contemporary sense, Mr. Kazin demonstrates. Bryan’s politics were liberal verging on the socialistic (he thought the railroads, for example, should be nationalized). And though he opposed the teaching of evolution, he was not a literalist. If the earth was created in six days, those days, he suggested when Darrow cross-examined him, would be eons in our terms.

Bryan decried Darwin’s “survival of the fittest” because it had been interpreted to mean that society had no obligation to help the weak. Similarly, he became alarmed when eugenicists used Darwinism to advocate the development of a healthier species, marking the disabled for elimination.

In Bryan, the biographer finds a figure whose appeal cut across supposedly divided voting blocs to include populists (working class) and progressives (middle class). Indeed, a lot of Theodore Roosevelt’s rhetoric, Bryan himself pointed out, was pure Bryanism – even though TR despised Bryan.

Bryan never won a national election, because he failed to attract enough urban voters or take full advantage of the nascent labor movement. Although he failed three times to capture the presidency, Bryan was immensely popular. He was a great speaker, even making the transition from addressing large crowds without the aid of microphones to, in his last years, triumphing in the new medium of radio.

Bryan could make a political position seem like a sacred principle: Going off the gold standard and increasing the money supply by switching to silver became the equivalent of Christ throwing the money changers (the Republicans) out of the temple: “You shall not press down upon the brow of labor this crown of thorns, you shall not crucify mankind upon a cross of gold.” Bryan dramatized his Cross of Gold speech, delivered to the 1896 Democratic convention, by stepping back from the podium, pulling his hands away from his brow, and extending them straight out from his body, holding the Christlike pose for perhaps five seconds, Mr. Kazin reports.

Bryan spoke to the “heart of America,” his wife, Mary, said. But Mr. Kazin calls her answer too sentimental:

It fails to grasp the historical context for Bryan’s popularity and neglects the fact that he often challenged his audiences with political talks – from recitals of the Cross of Gold speech to long critiques of World War I and arguments for prohibition and woman suffrage. Neither does it explain what he meant to these Americans – in small cities as well as crossroads villages – that other well known speakers on moral topics did not.

Bryan came of age, continues Mr. Kazin, before the advent of modernism, before the likes of John Reed and the bohemian left ridiculed him as an old fogy, before the disjunction between a Christian left and secular reformers became so wide that many of the commoners Bryan called on in building the Democratic Party had deserted it, understanding that their faith was a subject of ridicule.

Mr. Kazin contrasts John Reed’s magazine, the Masses, and Bryan’s periodical, the Commoner, in order to show where the left went wrong.The former was irreverent and witty and the latter earnest and righteous. Even in his declining days, however, Bryan was able to “embellish his reputation among people that John Reed could never reach. A Presbyterian minister in Michigan wrote to Bryan: ‘I want you to know that I am one of the thousands of young men in this country that you have helped into lofty conceptions of life and its meaning.'” Mr. Kazin concludes that Bryan represented the

yearning for a society run by and for ordinary people who lead virtuous lives. As everyone who heard him could attest, Bryan made significant public issues sound urgent, dramatic, and clear, and he encouraged citizens to challenge the motives and interests of the most powerful people in the land.That is a quality absent among our recent leaders, for all their promises to leave no man, woman, or child behind.

With such sentences Mr. Kazin is using biography not only to show how his subject was true to himself and his cause, but also to explain how history was once made.

crollyson@nysun.com