A Woman in Charge: The Life of Hillary Rodham Clinton By Carl Bernstein Knopf 629 pages; $27.95 After eight years in the White House and seven in the Senate, Hillary Rodham Clinton is a credible candidate for the office of president of the United States. But at this stage of her career, a longtime associate believes, she should be more aggressive and less inclined to glance at the rearview mirror: "Besides, I'm not sure I want the circus back in town." These days, most Americans prefer a circus to a chamber of horrors - even if the donkeys replace the elephants and a Clinton becomes the ringmaster. At the moment, Hillary Clinton is leading the parade in the race for the Democratic nomination. One of the most polarizing figures in American politics, Hillary can run, but she can't hide. Nor can she avoid being scrutinized, analyzed, canonized and criticized. A Woman in Charge is one of the best in a slew of biographies of the former first lady, who refers to herself as "a mind conservative and a heart liberal." Drawing on about 200 interviews with friends and foes, Carl Bernstein, the Washington bureau chief for ABC TV, who shared the Pulitzer Prize with Bob Woodward for their coverage of Watergate in The Washington Post, portrays Clinton as a work-in-progress, who evolved from Goldwater Girl to left-wing Democrat, from "risky, unequivocal" advocate to cautious, establishment politician. Bernstein appears to have no partisan pickaxes to pulverize, though he does go further than the evidence warrants to flog his thesis that Clinton was in charge at the governor's mansion in Little Rock, Arkansas, and in the West Wing of the White House. He isn't really able to reveal the essence of her character or her political philosophy, but he provides a savvy and sobering account of the ideas, instincts and actions of the woman who may well become the most powerful person in the world. Bernstein begins by refuting Clinton's oft-repeated claim that she had an idyllic Midwestern upbringing. Hugh Rodham, he demonstrates, was a depressive and confrontational man. Since Dorothy Rodham did not believe in divorce, she served as shock absorber - and referee - for her daughter and two sons. To keep the peace, Hillary became an "enabler" as well. In the 1960s, at Wellesley, a college for women, Hillary moved steadily to the left. She supported civil rights for African-Americans and organized anti-Vietnam War protests. As student body president, she gave a Commencement Day address, improvising a response to senator Edward Brooke, who had defended the war and denounced "coercive protest." Life magazine captured the moment, with a photo of Ms. Rodham in Coke-bottle glasses and "striped bell-bottom trousers, her hair a mangy tangle." One of only 27 women at Yale Law School, she wrote scholarly articles about women and the law, prepared for a career in public advocacy - and fell in love with the charismatic Bill Clinton. She hesitated to marry him because of his infidelities and her suspicion that she couldn't be a woman in charge in provincial Arkansas. But after a stint as a congressional staffer, helping to prepare the case to impeach Richard Nixon, she tied the knot. In 1978, Bill Clinton became the youngest governor in the history of Arkansas. He was defeated for reelection, Bernstein suggests, in no small measure because his feminist wife worked at the Rose Law Firm and retained her maiden name. To help "the comeback kid" return to power, she became Hillary Rodham Clinton. Then - and later - she wielded plenty of power. Appointed by Bill as chair of the Education Standards Committee in Arkansas, she designed legislation that imposed curricular standards, class size and a competency test for teachers. In Washington, she was czarina of the ill-fated health care reform package. But she probably wasn't in charge. Portraying Bill Clinton as a passive president, afraid of his wife and swaying with the political breezes, Bernstein asserts, a bit hyperbolically, that she had "an attitude of entitlement," believed "she could solve any problem she applied herself to" and, when necessary, exacted "payback" for standing by her man. Clinton may well have wanted to close the corridor that gave reporters access to the West Wing and fire the staff of the White House Travel Office. She may have advised her husband not to compromise on health care, turn over Whitewater documents, or settle the Paula Jones suit. But didn't he remain "the decider"? And did she really staff the White House so that her influence would "almost always prevail" and vet cabinet appointments to "guard against surprises"? Bernstein does demonstrate that Clinton made mistakes when things went wrong. Facing criticism of her complicated - and secretive - health care plan, she threatened senators Bill Bradley and Daniel Patrick Moynihan, heavyweights in her own party, that the administration would "demonize" anyone who opposed passage of the bill. And she impeded investigations of Vince Foster's suicide and the Whitewater real estate deal. After the Republican takeover of the House and Senate in 1994, the "Lewinsky imbroglio" and the impeachment hearings, Hillary Clinton changed. The younger Hillary may never have been the firebrand, fighting for "principles with a capital P," conjured up in A Woman in Charge. But she did become more persuadable and pragmatic. Clinton agreed, for example, that her husband should sign welfare-to-work legislation, setting a five-year limit on government assistance to unemployed heads of families. Lately, Bernstein writes, thinking, no doubt, about Iraq, Hillary Clinton's public pronouncements have been "elaborately prepared and relatively soulless." On some issues, there's "a disconnect between her convictions and words, and her actions." An intelligent and astute politician, Clinton "still has time to effectuate those things that make her special." Will she seize the moment when she takes center stage? Or play it safe? "The jury is still out." The writer is the Thomas and Dorothy Litwin Professor of American Studies at Cornell University.