Hearing Barack Obama speak last week in Denver, I found it hard to avoid bittersweet memories of Dr. King's "I Have a Dream" speech at the March on Washington in August 1963. How far our country has come! And how much further we have yet to travel on Dr. King's road to peace and social justice! For me, one memory stands out, a small piece of history that throws new light on why many progressives find themselves faulting Obama for moving toward the right wing of the Democratic Party.

    A few days before the march, a battle-scarred hero of the civil rights movement came to the University of Michigan to practice the speech he planned to give in Washington as chairman of the Student Non-violent Coordinating Committee (SNCC). John Lewis was - and is - an Old Testament prophet, and his words heaped moral fury on President John F. Kennedy, a man whom young civil rights activists at the time did not see as on our side.

    If JFK wanted to support meaningful political and economic rights for the poorest black share croppers, that was good, said Lewis. If JFK did not, the movement would rise up without him like Sherman marching through Georgia.

    Inspired, several of us from Ann Arbor trooped off to Washington. There we were, right in front of the Lincoln Memorial, waiting for Lewis to give his speech and singing, "If Kennedy gets in the way, we'll roll right over him."

    How wrong we were! On that day at least, JFK rolled right over us. If Lewis insisted on giving his speech as he had written it, the Rev. Eugene Carson Blake of the National Council of Churches threatened to withdraw from the list of speakers, as did other Kennedy supporters. Lewis softened his remarks. We continued to sing. And no one heard us.

    I learned a lot about free speech that day, and about the willingness of so many good-hearted liberals to exercise their own power over who should speak and what they should be allowed to say. But something else was so obvious that I did not truly grasp its significance until last week, when I saw and heard the video of Obama's big speech.

    At the March on Washington, John Lewis was speaking for a civil rights movement that JFK had not created and did not control. The following summer, SNCC organizers showed up at the Democratic National Convention with the Mississippi Freedom Democratic Party, creating a nightmare for Lyndon Johnson and dramatically breaching the wall of legal segregation.

    Today, the social dynamics are back to front. The civil rights movement has become history. The antiwar movement has grown quiescent. Progressive Democrats of America and other groups are just starting to show their strength. And aside from Netroots Nation and some stirring in the unions and among immigrant groups, the only thing resembling a mass social movement is the awesome electoral campaign that Obama has created around himself.

    A candidate-centered movement can certainly win an election, but can it bring green energy, green jobs and universal health care once the election is over? Obama's recent moves to the right suggest the answer, as does the rightward shift away from Bill Clinton's populist message during his first term. For Obama's hopes to become real, America needs an independent progressive movement that is bigger than even the most inspiring political leader, and powerful enough to counter the inevitable onslaught from Wall Street democrats and foreign policy hawks, neo-libs and neo-cons, and an army of highly paid lobbyists.

    Just because George W. Bush and Dick Cheney are leaving the White House in January, Big Oil will not slip into the sunset; arms makers will not beat their swords into ploughshares, and managed-care conglomerates will not make serious health care a higher priority than their corporate profits. Few on the top want the America that Obama has promised, and even if elected with an overwhelming mandate, Obama cannot deliver on his promises without millions of Americans who know how to keep up the post-election pressure on Congress, on the corporate media and on him.

    Change we can believe in, change that we need, requires a mass movement we can count on. No independent mobilization, no serious change. But the missing movement is not Obama's fault, and organizing it is not his job. It's ours, as progressives. And, in my opinion, it's bogus to bash Obama for giving in to Robert Rubin and Zbigniew Brzezinski if we're not building a political force to outpush them.

    Should we point out where we think Obama falls short? Absolutely. Anything less would distort a reality that's there for everyone to see. But Obama's hope is America's hope, and if we do not work our hardest to elect him president even as we build an independent progressive movement, we will have squandered the best opportunity our country might ever have. So, let's get on with the job. To paraphrase the old rallying cry, "Don't Moan, Organize."