Speaking in the Democratic radio address, retired Army Gen. Wesley Clark called the vote "an important step toward a democratic Iraq." Still, he said, "let's not kid ourselves about the difficulties that lie ahead." Defeating the insurgency, winning the support of alienated Sunnis, training Iraqi forces and rebuilding the country's infrastructure and economy remain formidable tasks, he said.

For some Sunnis, a vote against the constitution was in part a statement of rejection of the U.S. occupation. But for most, the vote appeared to signal their entry to Iraq's political process in hope of regaining some control over their future — if not by defeating the charter, then by winning seats in December's parliamentary elections and working to amend it.

"If these people get power, we will never see stability in Iraq again," said Khalaf Ahmed Khalif, 53, a farmer in Ishaqi, an area of lush farmland amid arid desert in Salahuddin province. "If you think it's bad, just think about double the number of forces the Americans have in the country right now."

In Ishaqi, 300 people voted in January's elections for a transitional government. By late Saturday afternoon, 9,350 had turned out.

The turnout was also high in several larger cities across the mostly Sunni province, including places where the U.S. military has waged a nearly continuous battle against insurgents. Samarra, which reported 35,636 voters by mid-afternoon, had run out of ballots and was requesting more from U.S. commanders.

Not all Sunnis voted no. In Baghdad, some said they voted for the charter because of security concerns, hoping that the next step would be rule of law.

"I insisted on voting, even though my neighbors told me it would be dangerous," Haifa Ahmed Satoor, 38, a government worker and a Sunni, said in Baghdad before voting yes.

"I don't want more people killed in the name of Sunni resistance," Satoor said. "We already lost neighbors — I don't want to lose relatives."

In Sadr City, a vast Shiite area in northeast Baghdad, Mayyada Ahmed already had. She came to a polling center to vote for the draft on the final day of mourning for a cousin shot by Americans at a checkpoint, a few weeks after three other male relatives were abducted from their home and later found dead in heaps of garbage.

"We came because we hope the future will be better," Ahmed said, reflexively waving her ink-stained finger in a now-worn symbol of hope from the last election. "We are hoping it will provide safety. We will keep voting until it does."

U.S. troops in Baghdad and most of the country yielded election security to Iraqi forces, save for American convoys that rumbled through Baghdad. As in January, a one-day ban on private vehicles helped block suicide attacks. Iraqi troops manning checkpoints fell into impromptu soccer games with children, who poured into the streets, rollerskating and biking through the city on Baghdad's most peaceful day in months.