PATRIOTIC GRACE Peggy Noonan's Wall Street Journal column has been must reading for thoughtful liberals and conservatives alike. Now she issues an urgent, heartfelt call for all Americans to support the next President. Because it is not the threats and challenges we face, but how we face them that defines us as a nation.   The terrible events of 9/11 brought us together in a way not seen since World War II. But the stresses and divisions of the Bush years have driven us apart to a point that is unhealthy and dangerous. Today, Noonan argues, the national mood has swung the other way and it is well past time for politicians to catch up. We long for leaders who can summon us to greatness and sacrifice, as they did in the long struggles against fascism and communism.   In this timely essay, written in the pamphleteering tradition of Tom Paine's Common Sense, Noonan reminds us that we must face our common challenges together—not by rising above partisanship, but by reaffirming what it means to be American.