In what is becoming a disturbing summer ritual, every August the right wing drops a sputtering bomb of chaos and confusion on the American public; in response, the left freaks out. Last year it was the hysteria over "death panels," sparked by Sarah Palin. This year it’s the one-two punch of the "Ground Zero Mosque" controversy and Glenn Beck’s "Restoring Honor" rally at the Lincoln Memorial, forty-seven years to the day after Martin Luther King Jr.’s "I Have a Dream" speech at the same location. To be sure, there’s plenty to get worked up about: these incidents are an affront to truth, history and decency. It’s important to debunk the right’s myths and to defend those under scurrilous attack: Imam Rauf is not a radical Islamic terrorist; neither, for that matter, is Barack Obama.

But let’s get a grip. The president, as he recently reminded us, is not going to walk around with his birth certificate pasted to his forehead—not that it would assuage the 52 percent of Republicans who believe he wants to impose Sharia law on America. And the left isn’t always going to be able to out-tweet Palin or win every twenty-four-hour news cycle—nor should that be our goal. Our politics are not just about what we are against, or want to "take back" or "restore"; they are about what we want to achieve.

So let’s look to other, more august speeches as a reminder of that broader vision. In his famous address at the March on Washington for Jobs and Freedom, King deplored not just discrimination but the "poverty in the midst of a vast ocean of material prosperity" that racism creates. Later, in his last speech as president of the SCLC, King called for a guaranteed annual income, because "no matter how dynamically the economy develops and expands, it does not eliminate all poverty." That same year, King broke his silence on the Vietnam War, calling not just for an end to that occupation but to all war because "war is no longer, if it ever was, a valid way to solve international problems."

These are radical utopian goals—and they are worth rekindling. Part of what so rankles the left about the Tea Party is its vigor and ambition. But why should the left not dream as large and as loud? Yes, the opposition is fired up—motivated by racial, religious and economic anxiety. Yes, it’s well funded by billionaires like the Koch brothers, Rupert Murdoch and Paul Singer. Yes, the political system is crippled by cynical obstructionism. But these obstacles also create openings. If the Republicans intend to filibuster even the most meager jobs bill, then let’s put forward a $1 trillion stimulus to move the economy not just toward recovery but reconstruction, allying with those in Congress who would do the same. If the right wing continues to smear Muslims, let’s not limply defend the freedom of religion, let’s celebrate multicultural America in all its vibrant, polyglot cacophony. Let’s embrace the new American majority we saw emerging in the 2008 election. And let’s storm Washington with our own rallies, like the October 2 March on Washington organized by labor, the NAACP and student groups.

The ugly backlash will still come. And it may take more than a generation to realize these dreams. But that is not cause for despair, for the genius of King’s rhetoric was in marrying the "fierce urgency of now" to an enduring vision, to "the long and bitter, but beautiful, struggle for a new world." These are words to savor: it is not the end that is exquisite, but the dream, the hope, the struggle. The struggle itself is beautiful.