Pitching her tent on the Texas roadside, Gold Star Mother Cindy Sheehan has given a face, a voice and a story to the widespread but amorphous disillusionment with George Bush’s Iraq occupation. Truck drivers divert from the interstate to blare their horns in support. Dozens of veterans and dead soldiers’ families brave the summer heat to join her. Network news programs lead their morning broadcasts with the story of her protest.

The President, unwilling to accede to Sheehan’s demand for a meeting and aware of the explosive potential of the war-bereaved, utters a generic statement and roars by in a limo to avoid the possibility of direct confrontation.

It’s easy to dismiss Cindy Sheehan’s moment as the product of fortuitous circumstance: the slow news cycle of August, a bored White House press corps stuck in Crawford and desperate for any alternative to yet another shot of the vacationing President hacking down weeds. All of that is true. But there is more to this.

Sheehan set out for Crawford–what she describes as a “spontaneous” decision–at what may turn out, in retrospect, to be a critical juncture in the war: The week news polls showed fully 61 percent of the public opposed to the President’s Iraq policy. By demanding to talk with the President about her son, Sheehan is in essence asking the country to pause and contemplate not the daily death count from insurgent bombing, not numbing policy debates but the meaning of Casey Sheehan’s single corpse.

Sheehan has often over the last week been compared with Rosa Parks, but a better analogy is Mamie Till Mobley, who in 1955 galvanized the nascent civil rights movement by insisting that the brutalized body of her lynched son Emmett Till be displayed in an open casket.

The meaning of death is no casual political question. As World War II demonstrated, families will absorb unspeakable loss if they are convinced it serves a purpose. The bitter irony of Iraq is that US soldiers’ deaths diminish in meaning the longer the occupation persists. In that loss of meaning lie the seeds of a profound betrayal.

It needs to be said, too, that Sheehan’s protest has succeeded because “meet the President” is such a viscerally reasonable demand–far short of “stop the war,” which to many still seems an overwhelming and distant prospect. Any television viewer, regardless of politics, might imagine how Abraham Lincoln would have treated the mother of a dead Union soldier who camped out on his doorstep. Even President Bush could have short-circuited Sheehan’s protest on its first day had he had jogged down the driveway with his Secret Service detail and politely invited Casey Sheehan’s mother in for a quiet cup of coffee.

If Sheehan’s protest is full of hazards for the President, the antiwar campaign also needs to be heeding this moment’s lessons. For starters, let it be noted that each critical turn in public perception of the Iraq war has been driven by a measured act of civil disobedience by individuals within the military’s expansive penumbra: the leaking of classified Abu Ghraib photos, the decision by military lawyers to break the chain of command and go public about Guantánamo abuses and now Cindy Sheehan’s stoic protest. In each case, those with the most direct stake in US policy took a stand and said, “Enough.”

It’s important, too, not to overstate the significance of the public’s turn away from the President. Disillusionment is not the same thing as protest, and a media moment is not the same thing as sustained public attention. The White House hopes the interest of the press corps in this story has crested, that the protest has already become old news, that Sheehan’s media appeal will fade.

In the short run, only some dramatic development–a massive influx of Sheehan supporters to Crawford–is likely to prove the White House wrong. And in the longer run, for Cindy Sheehan and the national and local planners of antiwar protests, the important question is, What next? What will it take for the grief of parents and spouses, and the anger of antiwar veterans, to become a genuine force upon the landscape?