Unless you were old enough to remember the mid-1960s, it might be hard to grasp the impact the Kennedy family had on the popular imagination and political discourse. Everything the Kennedys did seemed to be news, even if it was just Jackie sporting a miniskirt in public. This intense level of scrutiny, sparked by President John Kennedy's 1963 assassination and fueled by a yearning for what once was and might be again, kept the family in the spotlight.

Patience was not a virtue in the 1960s. The decade was all about change. Into that world and time strode Robert Kennedy. He was, as Larry Tye's new biography, "Bobby Kennedy: The Making of a Liberal Icon," shows, a man on a mission even if he wasn't, perhaps, fully aware of where the mission would go.

Tye's well-researched and carefully sourced book details how Kennedy used forward thinking to address the major issues of that rapidly evolving decade. He saw change coming and turned to meet it.

"A revolution is coming — a revolution that will be peaceful if we are wise enough, compassionate if we care enough, successful if we are fortunate enough, but a revolution that is coming whether we will it or not," Kennedy wrote.

While that "revolution" wasn't as great as the left hoped for and the right feared, America was a profoundly different place at the end of the decade than at the beginning. Tragically, Robert Kennedy would not live to see the country he was working so hard to change.

Kennedy's assassination in 1968, minutes after winning the California Democratic primary for president, cut short a life that was, as Tye so carefully lays out, one in progress.

Kennedy began as a man who saw things starkly in basic terms, like good and evil, working for Sen. Joseph McCarthy, the Wisconsin Republican who fueled a Communist witch hunt; laboring tirelessly to get his brother into the White House, and doing anything to score an administration win. At the end of his life, Kennedy was increasingly his own man who, matured by grief and more open to life's complexities, had become an eloquent champion for the poor and the oppressed.

RFK's record on civil rights, his wrangling with the Russians over Cuba, his crusade against organized crime and the way he waged various Kennedy campaigns are all examined in this book. It's clear Kennedy's metamorphosis to "liberal icon" didn't happen immediately or easily.

Along the way, Kennedy amassed a formidable list of people who disliked or hated him, including Frank Sinatra, Secretary of State Dean Rusk, FBI Director J. Edgar Hoover, writer Gore Vidal, Sen. Eugene McCarthy, Teamsters President Jimmy Hoffa and President Lyndon B. Johnson. Yet, he was able to win over countless others because he had the courage to change, to evolve and to respond.

Tye is a Massachusetts-based author and journalist who has covered the family "repeatedly" for the Boston Globe and interviewed members of the Kennedy family, including RFK's widow, Ethel. He presents a balanced portrait of his subject that gives equal due to Kennedy's achievements and failures in and out of the public eye.

Readers looking for titillation or confirmation of rumors probably will be disappointed. Tye dispassionately presents the claim, looks for proof, concludes that "no one knows for sure what happened when the doors were closed" and moves on.

In a sense, Tye has to keep going, for Robert Kennedy's life moved too quickly to allow the biographer to linger long in the bedroom. And short, how short, his life was. Dead at 42 — how could Kennedy have done so much, so fast, so young?

"Half Che Guevara, half Niccolo Machiavelli, Bobby was a shaker-upper dedicated to the art of the possible," Tye writes in the preface.

"That he could change so substantially and convincingly over the course of his brief public life helped restore a changing America's faith in redemption. In the end he could become this nation's high priest of reconciliation precisely because he had once been the keeper of our darkest secrets."

Bill Daley is a writer for the Chicago Tribune.