Toward the end of the remarkable speech he delivered to the mourning citizens of Tucson Wednesday night, President Obama recalled that a photo of the youngest victim of Saturday’s shooting rampage—9-year-old Christina Taylor Green—was featured in a book about children born on September 11, 2001. Next to the photo were "simple wishes for a child’s life," one of which read: "I hope you know all the words to the National Anthem and sing it with your hand over your heart."

The crowd of 14,000 that had gathered to celebrate the lives of the six people who died Saturday and to pray with Obama for the recovery of those who were wounded—including Arizona Congresswoman Gabrielle Gifford—cheered the reference to a simpler, more innocent and more humane patriotism that stood in such stark contrast to the vitriol of contemporary politics.

It has been said that Obama strives for a post-partisan balance. But this was Obama speaking as a pre-partisan, as an idealist recalling a more innocent America—and imagining that some of that innocence might be renewed as shocked and heartbroken citizens seek to heal not just a community but a nation that is too harsh, too cruel, too divided.

"If this tragedy prompts reflection and debate, as it should, let’s make sure it’s worthy of those we have lost. Let’s make sure it’s not on the usual plane of politics and point scoring and pettiness that drifts away with the next news cycle," Obama told a crowd that included members of Congress from both parties, including the Republican he defeated in the 2008 presidential contest, Arizona Senator John McCain (but not McCain’s controversial running mate, Sarah Palin).

Cautioning against a politics that seeks "to lay the blame for all that ails the world at the feet of those who think differently than we do," and he suggested that the way to do this is by recognizing it’s the value of "talking with each other in a way that heals, not a way that wounds."

Obama’s language recalled the most idealistic appeals not just of his own political journey but of past presidents—Lincoln, FDR, Reagan and Clinton—when they sought to heal a torn or traumatized nation.

"The loss of these wonderful people should make every one of us strive to be better in our private lives—to be better friends and neighbors, co-workers and parents. And if, as has been discussed in recent days, their deaths help usher in more civility in our public discourse, let’s remember that it is not because a simple lack of civility caused this tragedy, but rather because only a more civil and honest public discourse can help us face up to our challenges as a nation, in a way that would make them proud. It should be because we want to live up to the example of public servants like John Roll and Gabby Giffords, who knew first and foremost that we are all Americans, and that we can question each other’s ideas without questioning each other’s love of country, and that our task, working together, is to constantly widen the circle of our concern so that we bequeath the American dream to future generations," Obama explained.

"I believe we can be better. Those who died here, those who saved lives here—they help me believe. We may not be able to stop all evil in the world, but I know that how we treat one another is entirely up to us. I believe that for all our imperfections, we are full of decency and goodness, and that the forces that divide us are not as strong as those that unite us," the president continued.

"That’s what I believe, in part because that’s what a child like Christina Taylor Green believed. Imagine: here was a young girl who was just becoming aware of our democracy; just beginning to understand the obligations of citizenship; just starting to glimpse the fact that someday she too might play a part in shaping her nation’s future. She had been elected to her student council; she saw public service as something exciting, something hopeful. She was off to meet her congresswoman, someone she was sure was good and important and might be a role model. She saw all this through the eyes of a child, undimmed by the cynicism or vitriol that we adults all too often just take for granted.

"I want us to live up to her expectations," Obama concluded. "I want our democracy to be as good as she imagined it. All of us—we should do everything we can to make sure this country lives up to our children’s expectations.

The president chose in Tucson to present an almost absurdly idealistic appeal to a "one nation" Americanism that only the most hopeful of our leaders—and the most hopeful of our citizens—have dared imagine. Obama took a risk in expressing it. His critics will, as is their wont, accuse him not just of naïveté but of cynicism.

So be it. We are a better nation when we are undimmed by cynicism and vitriol. And for a few minutes on Wednesday night, we dared with our president to answer cynicism with idealism, to answer tragedy with hope, to answer division as one nation, indivisible.