As if the physical resemblances, both natural and cultivated, weren't enough, John Edwards now explicitly casts his presidential campaign as a sequel to Robert F. Kennedy's. Just as Kennedy did way back in the Sixties, Edwards stakes his claim as champion of all those Americans who struggle for a place on the ladder of material success, even a bottom rung.

True, Edwards hasn't helped himself with the contradictory signals sent by expensive houses and haircuts. But what would we rather have -- a politician perhaps running interference for the Halliburtons and health insurers of the world, or one who willingly assumes the role of advocate for the poor? Even if he's plenty rich himself.

The question is whether that role can give Edwards the traction he needs. He has fallen well behind Hillary Clinton and Barack Obama in the high-stakes fundraising competition, and Obama makes it clear he won't let Edwards corner the anti-poverty market.

Beyond that, do the struggles of the poor engage today's voters sufficiently to outweigh the burning national security issues -- i.e., frustration with a bollixed war amid a gathering terror threat -- that have given Democrats so much momentum? Edwards' critique of the Bush team's Iraq misadventure is as forceful as anyone's, but his campaign's distinguishing mark so far has been its throwback emphasis on the kind of domestic themes that worked so well for Bobby Kennedy.

But that was then. Not only were the late 1960s cursed with their own, far more costly and destructive war, but that was a time of unprecedented social turmoil tied to bitter divisions over race and class.

Poverty was at the root of the troubles. And while mostly white Appalachia also had become a symbol of this country's ragged edge, the worst concentrations of poverty and hopelessness were to be found in the big cities, where black residents were crowded into miserable slums.

The resentment exploded even as Congress, urged on by President Johnson, finally had enacted civil rights and voting rights laws that were quantum leaps toward racial equality.

Watts, the black ghetto in Los Angeles, was ripped by destructive riots in the summer of 1965, setting a pattern for the long, hot summers to come. Forty years ago this month there were massive, days-long riots in Newark and Detroit -- signature episodes of violent social protest.

Cops and National Guardsmen by the hundreds fought to quell rioters far gone into looting and arson. Dozens died, and property damage was astronomical. Before that summer of 1967 finally sputtered out, in fact, rioting had erupted by one account in no fewer than 114 U.S. cities in 32 states.

A history of Durham notes that a July protest march left broken windows and other damage downtown. The narrative continues: "After several demonstrations turned into near-riots, as white hecklers and racists confronted the demonstrators, and as lone arsonists repeatedly chose targets at random to vent their anger, the mayor called in the National Guard to prevent further violence." Through business boycotts and further agitation, black residents finally registered some of the gains they had sought, especially in the areas of housing, jobs and public safety.

The overall picture during that wretched period was so dire that Johnson convened the National Advisory Commission on Civil Disorders. The panel's report became a landmark of unflinching national self-assessment. It included this famous diagnosis: "Our nation is moving toward two societies, one black, one white -- separate and unequal."

Johnson, soon to be entangled in the all-too-real war in Vietnam, already had declared his symbolic War on Poverty. The last legal forms of racial discrimination had been abolished. But it was not enough for a younger generation of black activists who saw violence as a legitimate political tactic. The greatest exponent of nonviolence, the Rev. Martin Luther King Jr., would not survive into the next summer to serve as a counterweight to the rising Black Power movement.

It was Bobby Kennedy, in his 1968 dash for the nomination after a war-weary Johnson declared he would not seek a second term, who picked up the anti-poverty cause and made it his campaign signature. It might have worked had not Kennedy also fallen to an assassin's bullet.

Kennedy had finished off one campaign swing in the Appalachian town of Prestonsburg, Ky., and it was there that Edwards last week reprised his theme of a nation consisting of "the very rich and everybody else."

"I want America to join us, all of us, to end the great work Bobby Kennedy started," Edwards told his audience. Of course, it will never end unless that divide between black and white, noted so painfully after the riots of 40 years ago, also can at last be healed.