Rush Limbaugh is one of America's most polarizing figures. Perched at the intersection of politics and entertainment, shunned by most of the nation's cultural elites but revered by millions, the bombastic Cape Girardeau, Mo., native is worthy of study.

And yet, not much serious, nonpartisan biographical work has been done on Limbaugh. So he was a natural subject for author Zev Chafets, a former newspaper columnist who wrote a piece on the radio host for the New York Times Sunday Magazine.

Although Limbaugh was wary at first, Chafets eventually persuaded him to agree to a series of interviews and e-mail exchanges. Such material allows the author to quote Limbaugh at some length on various issues. And Chafets uses extensive excerpts from Limbaugh's radio show to illustrate how he uses hyperbole, satire and confidence in a bedrock conservative belief in limited government to make his points.

But despite such access, Chafets' book is far from the serious, detailed biography that Limbaugh's stature so clearly deserves.

Chafets begins by taking the reader on a quick trip to Cape Girardeau, unnecessarily inserting himself into the narrative from the start. In chats with Limbaugh's younger brother, David, and boyhood friend Frank Kinder, brother of Missouri Lt. Gov. Peter Kinder, Chafets gathers only a fleeting portrait of his subject's early life. He wastes space on such unrevealing quotes as this one from Frank Kinder: "We more or less grew up in each other's houses."

On driving to Cape Girardeau from St. Louis, the author allows that the farmland "offers no temptation to stop or sightsee," and he shares his surprise to find Tennessee Williams on the town's Wall of Fame: "I had no idea Tennessee Williams was from Missouri."

It is the kind of "drive-by journalism" that Limbaugh so often derides.

The book moves ahead in similar fashion, tracing Limbaugh's indifferent academic progress and his obsession with radio. We meet "Big Rush," Limbaugh's father, who is presented as vaguely disappointed. Although we are told that pleasing his father remains a driving force in Limbaugh's life, we get little idea of why.

We learn that as a radio professional, Limbaugh bounced around several disc jockey jobs before settling on political talk as a format. It seemed a natural fit. But why did he choose politics? The answer isn't clear, at least not in this narrative.

We trace Limbaugh's rise, his clash with Bill Clinton and the emergence of his "Ditto-head" army of followers. We hear that theatrical voice vilifying liberals, welfare recipients and, in a bit Limbaugh later apologized for, AIDS patients. And we learn about his loss of hearing and his addiction to prescription painkillers — but only what Limbaugh has already publicly acknowledged.

And, of course, we find Limbaugh thriving under the Barack Obama presidency, thrilling his listeners with his "I hope he fails" routine among others.

Chafets offers little analysis of Limbaugh's success, nor does he get particularly revealing thoughts from his subject. "Limbaugh had been concerned about Obama's view of America for a long time," Chafets writes. "From his perspective, he was right to be." Well, yes, I imagine he was.

Whatever you think of his views or his style, Rush Limbaugh is a tremendously influential leader of millions of culturally conservative listeners, if not the Republican Party. His life and career deserve a rigorous review. Unfortunately, Chafets provides more of an expanded magazine article than a serious biography.

"Rush Limbaugh: An Army of One" by Zev Chafets; Sentinel (229 pages, $25.95)