Friday was the 40th anniversary of the death of Robert F. Kennedy. Had he lived, he would be 82 now.

    It's impossible to gauge the what-ifs of history. But nevertheless, I wonder what Kennedy, a complicated man with a profound sense of the moral issues at play in politics, would have made of the idea that Barack Obama has captured the Democratic Party's nomination for president.

    He might not have been surprised. Kennedy had been accused of dreaming when he said in the early 1960s that a black person could get elected president in the next 40 years.

    The fact that even a dreamer could imagine nothing shorter than a 40-year timeline gives us a glimpse of the nightmarish depths of racial oppression that people of goodwill have had to fight.

    The United States in 1968 (the same year in which the Rev. Dr. Martin Luther King Jr. was assassinated) was a stunningly different place from the country we know now, so different that most of today's young people would have trouble imagining it. The notion in '68 that a black person - or a woman - might have a serious shot at the presidency would have been widely viewed as lunacy.

    Thurston Clarke, in his new book about R.F.K., "The Last Campaign," tells of the time that Kennedy was touring a Ford plant in Indiana. A white assembly-line worker refused to shake the presidential candidate's hand, telling Kennedy, "Get your [expletive] nigger-loving presence out of here."

    George Wallace also ran for president in '68. He was famous for "standing in the schoolhouse door" to block the court-ordered admission of black students to the University of Alabama. Wallace's views on racial matters were unequivocal. His mantra was: "Segregation now! Segregation tomorrow! Segregation forever!"

    The winner of the election was Richard Nixon, riding the G.O.P.'s soon-to-be infamous, racially polarizing and remarkably successful Southern strategy.

    A black man president? You must be joking.

    Women in 1968 were mired in depths of misogyny that were as soul-destroying as racism. Discrimination on the basis of gender was so pervasive as to barely attract notice. Many retail stores refused to issue credit cards to married women in their own names. Employers could fire women with virtual impunity if they got married or pregnant or weren't attractive enough or turned 30.

    According to the National Organization for Women, in a statement of purpose issued in 1966, fewer than 1 percent of all federal judges were women, fewer than 4 percent of all lawyers, and fewer than 7 percent of doctors.

    Racism and sexism have not taken their leave. But the fact that Barack Obama is the presumptive nominee of the Democratic Party, and that the two finalists for that prize were a black man and a white woman, are historical events of the highest importance. We should not allow ourselves to overlook the wonder of this moment.

    I was stopped on the street the other day by a woman who was holding the hand of a little girl, a toddler. After talking politics for a couple of minutes, the woman smiled and said: "Watch this." She then looked at her daughter and, referring to a certain presidential candidate, asked: "What's her name?"

    The little girl beamed and said: "Hil-la-ry!"

    That same night a middle-aged black man came to my apartment door with a food delivery. I'd seen him before, but he'd never said much, just sort of grunted a hello and a thank you. This time, after handing me the package and counting out change, he asked, shyly: "Did Mr. Obama win the nomination?"

    "Yes," I said. "He won."

    "For sure?"

    I said yes, and suddenly the widest grin spread across the delivery man's face. It was as though he'd been holding that grin in some hidden depth of emotional reserve for the entire campaign.

    This election year has been a testament to the many long decades of work and sacrifice by men and women - some famous, most not; some still alive, many gone - to build a more equitable and just American society.

    When the night riders were fitted for their robes, when Wallace stood in the schoolhouse door, when lowlifes mocked and humiliated those who were fighting for women's rights, they were trying to forestall the realization of this type of moment in history.

    We'll see whether Senator Obama gets elected president. But whether he does or not, this is a moment of which Americans can be proud, a moment the society can build upon.

    So a victory lap is in order. Not for Senator Obama (he still has a way to go), but for all those in every station in life who ever refused to submit quietly to hatred and oppression. They led us to a better place.