These days authenticity is a fetish. And for Democratic primary voters, no current candidate is deemed more authentic than Barack Obama.

Voters celebrate both Mr. Obama’s genuineness and salute his inspirational orations. His speeches are likened to those of Robert F. Kennedy and Martin Luther King Jr. Last week during his victory speech after the Iowa caucuses, he began by establishing a memorable rhythm and laying down words with repetition: “You know, they said — they said — they said this day would never come,” each phrase punctuated in a vaguely familiar pattern. For many commentators, the pattern, the tempo, was that of King, whose 1963 address in March at Washington is one of the most famous and powerful in American history. “Obama adopted the cadence of Martin Luther King, Jr.,” Timothy Grieve wrote in Salon. ” … he recalls the Rev. Dr. Martin Luther King, Jr. in his pacing and aching, staccato repetitions,” noted Michael Powell in the New York Times. “His speech was classic Martin Luther King,” reported the Mirror.

Mr. Obama’s victory speech in Iowa stood, along with his 2004 address at the Democratic National Convention, as among the best examples of the art of oratory in present day American politics. But there is a difference between the speaking styles of King and Mr. Obama. King grew up watching his father hold the pulpit at Atlanta’s Ebenezer Baptist Church for 44 years. His persona was stewed and marinated in the African-American religious culture of the South. Mr. Obama, on the other hand, grew up the son of a white mother from Kansas and a father from Kenya. Yesterday, Mr. Obama invoked King explicitly on the campaign trail. Speaking in Lebanon, N.H., he took aim at Senator Clinton’s cautioning voters against “false hopes.” He ridiculed her by depicting “Dr. King standing on the steps of the Lincoln Memorial looking out over that magnificent crowd” and imagining him saying “Sorry guys. False hope. The dream will die. It can’t be done.”

Later, Mrs. Clinton told Fox News that King’s dream required “Lyndon Johnson pass[ing] the civil rights act of 1964” an assertion that drew a sharp retort from Mr. Obama’s supporters.

The symbolic debate between Mrs. Clinton and Mr. Obama, “establishment politician” versus “activist,” is now explicit. But how did Mr. Obama become the King of our day? With all the talk of Mr. Obama’s authenticity, it’s remarkable that so few have wondered how this candidate can declaim like a Southern preacher.

Mr. Obama’s speech skills came later. It developed, says Reverend Eugene Rivers, who is the pastor of the Azusa Christian Community in Dorchester, Mass., and who has observed Mr. Obama’s style, from his time as a community organizer on Chicago’s South Side, an experience the senator often refers to on the campaign trail. Mr. Obama’s second book title, “The Audacity of Hope,” came from a sermon delivered by Jeremiah Wright, pastor at the Trinity United Church of Christ in Chicago, to which the candidate belongs. Reverend Wright’s father, like King’s, was a Baptist minister.

“He’s picked all this up working in the South Side of Chicago,” says Mr. Rivers, who is the head of the National Ten Point Coalition, a group that brings members of the clergy together with law enforcement officials to fight violent crime. “He’s been a student of the black church because at the end of the day, that’s where the power is,” he adds, referring to the senator’s days when he worked with churches and later ran for office in Chicago. Mr. Rivers attended the Harvard Divinity School around the time as when Mr. Obama went to Harvard Law School. The two men later met again at Saddleback Church in Lake Forest, Calif., where Mr. Obama and Senator Brownback discussed Reverend Wright.

The story of how Mr. Obama learned to become an orator suggests an interesting fact about this man who, at age 46, is young for a presidential candidate. He was, by his own telling, a late-bloomer who took on a major aspect of his public persona in his mid-20s. Whereas King developed his rhetoric during childhood. The public welcomes Mr. Obama’s style primarily because he is so good at it. But something more is at play. The public, saturated with King’s melodic sentences for more than four decades, also embraces Mr. Obama’s style out of a longing for the soothing, unifying leader he portrays himself as.

Jon Keller, the author of “The Bluest State,” a book about the political happenings in Massachusetts, contends that the group most hungry for a King-figure are members of the Baby Boom generation. “It’s a purifying, sanctifying process, whereby a politically failed generation, which is noted for it’s refusal to ever admit failure, is able to purge itself of its sins, by voting for a younger boomer who can redeem the entire generation by skin color and progressive politics and tone.” While Mr. Obama’s speech skills may not be as authentic as people would like them to be, the fact that his speech has been developed and trained should not be overlooked.

Mr. Gitell (gitell.com) is a contributing editor of The New York Sun.