John Tyler was the first vice president to assume the presidency, when William Henry Harrison died April 4, 1841, a month after he was inaugurated.

Harrison at 68 was then the oldest man to become president, running as a populist -- his campaign symbol was a log cabin -- although he was born to an aristocratic Virginia family.

Tyler, another Virginian, met with hostility when he took over the White House. Some referred to him as the "acting president" and "his accidentcy," but his strong character and decisive actions set the precedent for the six other VPs who were also accidental presidents.

For most vice presidents, however, their tenures were spent in obscurity and powerlessness. The job isn't worth "a pitcher of warm spit," as John Nance Garner put it euphemistically after eight years backstopping Franklin Roosevelt.

		"ANGLER: THE CHENEY VICE PRESIDENCY" By Barton Gellman The Penguin Press ($27.95)

Richard Cheney is the new model for the second-in-command. He's without question the strongest and most influential VP in history.

Barton Gellman, whose series on Cheney in the Washington Post is the source for his book, lays out the veep's unprecedented tenure action by action. (The book's title is the Secret Service label for Cheney, an avid fisherman and hunter.)

As Gellman makes clear, Cheney's power is due as much to the nature of President George W. Bush as it is to his own forceful, uncompromising personality.

Bush is "a big picture man" with no patience for detail or debate, writes Gellman, while Cheney's "brief, all in all, encompassed most of the core concerns of any president." Experienced in bureaucratic style, the VP did the legwork, Bush the signatures.

The president both needed and appreciated his VP's efforts, thus creating the sense of power Cheney wielded without oversight.

He even appointed himself Bush's running mate. Charged with selecting a candidate before the 2000 campaign, Cheney and his daughter Liz devised a comprehensive, humiliating questionnaire that demanded even the right to investigate financial and medical records.

He then flunked all prospects and advanced himself to Bush, who was uninterested in the ordeal of interviewing anybody.

Cheney, of course, didn't fill out his own form and has sealed the history of his serious heart disease from prying eyes.

What motivated Cheney was his deep belief that the presidency should be all-powerful, above Congress and the courts. It grew out of the humiliation of Watergate when Richard Nixon was brought to heel by the other two branches of government.

Nixon's statement -- if the president does it, it's legal -- became Cheney's philosophy, as Gellman demonstrates effectively and with wide sourcing from a variety of Bush administration insiders.

Some of this book has been published previously in Gellman's Pulitzer Prize-winning series co-written by Jo Becker.

But, there's much that's original including the extent of pressure exerted by Cheney on Justice Department officials sparring over the questionable wiretapping procedures and evidence that Cheney leaked private information on his rivals for VP in order to knock them out of the picture.

Vividly told are the chapters on the revolt within Justice over surveillance policies, including the standoff in a hospital room, the fall of Lewis Libby, one of Cheney's closest advisers, and the VP's behavior on Sept. 11, 2001.

The nation may never have -- or need -- a strong vice president like Richard Cheney again and Gellman leaves open the question as to whether Bush really required such strong direction.

His book, though, smartly demonstrates the good and bad of such an episode in presidential history.