Hillary Clinton’s victories in the New Hampshire and Nevada primaries have given supporters of Barack Obama reason for concern. The process is far from over, and it will be some time yet before the Democratic Party has a nominee. But one thing is clear: The euphoria that we Obama supporters felt after his comfortable victory in Iowa was premature, and the sense of Obama as an inevitable, “movement” candidate is gone.

There are few moments more disappointing than this, when it first becomes clear that a thing we have dared to fully hope for and believe in may not come to pass.

One of the most prominent issues of the Senator’s campaign has been the idea of hope. Obama has made it a central motif of his campaign, and it has been derided by the Clintons and other critics as an empty, vague word employed to shield Obama from nitty-gritty debates about policy.

But as an admittedly fervent and starry-eyed Obama supporter, I can bear witness to the reality of hope as an animating force of Obama’s campaign. Hope is more of a certainty than a wish; one who hopes walks into the future certain that things will work out one way or the other, even if events do not play out exactly as imagined.

“Be not afraid” is a religious assurance of hope powerful enough to resonate across the dividing lines of sects and centuries. Victor Frankl, a psychoanalyst and Auschwitz survivor, has written that a prisoner’s hope—his sense of faith in the future—was a key indicator of whether he would survive the concentration camps. Only hope, and certainly not “rational” self-interest, can explain the actions of anonymous protestors who stood in front of tanks in Tiananmen Square or soldiers who stormed the beaches of Normandy on D-Day.

The word “hope” signifies a powerful concept. Like most such concepts—love, faith, community—it represents something too big to fit comfortably into language. The person who uses the word, and especially the politician, is vulnerable to charges of unspecificity. But hope is a fundamental part of human life; the nature and cause of hope are shrouded in mystery, but that should not deter us from speaking of it.

What, exactly, are Obama supporters hoping for? What do we mean when we use the language of hope to describe what differentiates our candidate from the rest? It would be a small hope, unworthy of the name, if its ultimate aim were merely to install a politician in the White House, however extraordinary an individual he might be. As Obama himself regularly reminds his supporters, it isn’t just about him.

What we really hope for is a revolution in America’s political consciousness.

We hope for a country willing to elect a black president, for a country willing to acknowledge that the invasion of Iraq was a hubristic mistake, for a country that moves past blood-sport politics and toward respectful debate and dialogue, and for a country ready to recommit to a social compact that recognizes mutual obligations.

Barack Obama is only a vehicle for these greater hopes. Electing Obama would not mean that we have fully transcended racial division or conquered the temptations of militarism. But when I listen to Obama at his best, I imagine that such goals are possible and worth fighting for. I am proud to support a candidate who can kindle that spark of hopeful idealism and point the way to a better world.