DES MOINES, Iowa (AP) -- Democratic presidential candidate John Edwards told supporters last night to take back what he called "our democracy" from greedy corporations. Rock musician John Mellencamp's free concert helped put 3,000 people in a ballroom the night before the Iowa caucus. The former North Carolina senator gave an especially spirited version of his stump speech, tapping a vein of middle-class resentment and worry. Edwards is in a tight race with Hillary Clinton and Barack Obama in tonight's caucus, the first voting of the 2008 presidential election. No candidate has spent more time in Iowa than Edwards. In recent weeks, Edwards has sharpened his attacks on big oil, pharmaceutical and insurance companies. He's suggesting he would fight them far more ferociously than Obama or Clinton. (Copyright 2008 by The Associated Press. All Rights Reserved.)