Bald, his once-barreled chest now shriveled, Hassan Mehdi Mohammed hobbled Saturday into the polling station, housed in a worn-out school in the often-restive Sunni Arab neighborhood of Adhamiyah. His steel cane told his story: A veteran Arab nationalist and activist, his left leg was shattered by gunfire more than 40 years ago in a protest against one in a long line of Iraqi dictators. For a moment, he cast his glance at the two-story building around him.

"When I was young, I could have scaled these walls," he said, smiling.

On Saturday, the 73-year-old Mehdi fought what may be his last battle, in a time that he called the most difficult in Iraq's history. He came to cast his ballot against a constitution he believes will divide his country forever.

"I had to vote," he said, "to prove that we're still one nation -- Sunni and Shiite."

Saturday was a day of anger and desperation, regret and occasionally hope in Adhamiyah, a quarter of Baghdad whose very name has become synonymous with Sunni Muslim orthodoxy. Through the sometimes narrow streets that snake among low-slung buildings of tan brick beside the Tigris River, droves went to cast ballots in the referendum on a new constitution. There were men who had spent time in American detention, elderly people in wheelchairs, men who shuttered their shops and women clutching their children. Their numbers proved to be one of the day's most indelible images, and in contrast with the parliamentary elections in January, which the community largely boycotted, Sunni Arabs would have their say this time around.

Some said meekly that they supported the constitution, hoping for something better than the present. But in the crowded polling stations, more supported a "no" vote -- an endorsement of an imagined past over a promised future.

"We can't underestimate the value of Iraq. We want it to stay one, united," said Ibtihaj Ismail, an ailing 47-year-old woman who was helped by her family into a polling station in an elementary school. In front of a crowd, she marked her ballot "no" with a black pen.

Through the day, the referendum unleashed paroxysms of emotion among many in the Sunni Arab community, which for most of the country's modern history, and for centuries before that, guided Iraq through colonialism, coups, dictatorship and disastrous wars. More than two years after Saddam Hussein's fall from power, it remains on the outside looking in -- seething under occupation, alienated from a government dominated by the Shiite majority and Kurdish minority and, all too often, voiceless in its debates, fearful of the influence of Shiite-ruled Iran. Some saw their vote as a way to stake their claim anew to a country they consider theirs; to others, it was a last attempt to forestall its partition, the seeds of which many believe are contained in the roughly 140-article document that seems almost assured of being approved.

"The constitution is Persian. It's not Iraqi," said Jamal Alwan, 41, referring to the dominant ethnic group in Iran, as he headed to the polling station at the Noaman High School for Girls. His friend, 34-year-old Wisam Ali, nodded his head. He, too, was planning to vote "no."

"Do we vote for the massacres of Fallujah, for the massacres of Qaim?" Ali said, referring to Sunni cities in western Iraq where U.S. troops have fought insurgents. "The government is Persian, and the occupation is American. When the Americans withdraw from Iraq, then we'll agree on a constitution. God willing, we'll scuttle this one."

Like Lebanon's Maronite Christians, another minority that grudgingly surrendered power, Iraq's Sunni Arabs sometimes consider themselves the true defenders of their country, a patriotism that can bleed into chauvinism. Many voices barely disguised disgust at a government they see as dominated by long-repressed Shiites beholden to coreligionists in neighboring Iran. To the Sunnis, the foreign military presence in Iraq is unquestionably an occupation and, given the support the insurgency draws from their community, they often are the recipients of most of its humiliation.

Under a hot sun on a cloudless day, Alwan and his friends listed their grievances.

"Sectarianism," volunteered Alwan, who said he was detained by U.S. forces in southern Iraq during January's vote for the National Assembly.

"Stealing our resources and losing our rights," said another friend, Suheib Muhi.

"At the basis, it's the occupation," Ali said.

"And those who serve it," Alwan added.

Their sentiments were not universal Saturday. Qusay Abdel-Rahman carried his 3-year-old daughter, Nour, to the polling station. He would vote "yes," he said, "to guarantee the rights of the Iraqi people." A young woman who declined to give her name, conscious of the anti-constitution sentiments around her, said she too would endorse it. "I'm happy with the new people," she said quietly.

But more common was the mood of Ali Sami, a 33-year-old pushed in his wheelchair past a checkpoint.

"Why would I say yes?" he asked.

To Sunni Muslims, Adhamiyah's resonance is both modern and ancient. It houses the venerated Abu Hanifa mosque, where its namesake was buried in the 8th century after laying the foundation of one of Sunni Islam's most important schools of law. The mosque complex -- minarets, clock tower and brick walls bordered in turquoise -- still serves as a spiritual center of the community.

It was near there that Hussein made his last public appearance, atop a car in the waning days of the U.S. invasion in April 2003. For days, as the rest of the capital celebrated his fall and descended into chaos, his militiamen and soldiers fought on against U.S. troops. Graffiti hints at sentiments that persist: "Long live the resistance of Adhamiyah!"

"We wish that Saddam would return. Really, we wish," said Shaker Mahmoud, 47, waiting in a line of voters in the girls school's courtyard. His anger seemed to grow with each phrase. "If he did, we'd slaughter sheep and camels for him."

His friends looked down, perhaps a little embarrassed, and he turned more reflective.

"It's not an issue of Saddam," the stocky, unshaven Mahmoud said a few moments later, his words slowing. "Saddam is gone. It's a national issue. As Iraqis, as people of Adhamiyah, we are united, we have one word, one voice. As Iraqi people, we can't recognize this document. There are so many mistakes in the constitution. There are paragraphs in it that will destroy Iraq."

His words were desperate, spoken as though Adhamiyah were Iraq's last hope.

"The most honorable region in Iraq, all of it, is here in Adhamiyah," he said.

"And now it's become a city of ghosts," added a friend, Rafid Salman.

In other conversations, those sentiments usually unleashed a litany of complaints, common to Sunnis and Shiites alike: frustration with the lack of improvement in their lives, trash piled in the streets. One man complained he couldn't ensure his daughter's safety as she walked to school. For much of the morning, the polling stations were without electricity; the evening before, most Baghdad residents broke the dawn-to-dusk fast of the holy month of Ramadan in darkened houses.

"Government officials make millions, and people don't have ice to put in their drinks," said Bashir Eissa, a 50-year-old resident. "What's your opinion that I can sit here and see a person killed over there?" he said, pointing to a nearby bench.

Standing next to him was Ali Hussein, a swaggering 37-year-old. Like millions of others Saturday, he bore on his finger the indigo ink that Iraqis wore proudly as a symbol of their determination to vote in the election in January. For Hussein, the symbol had an altogether different message this time. He chose to stain his middle finger.

"This is to the constitution and to the people who drafted the constitution," he said, raising it in the air.

Disenfranchisement has become a powerful theme among Sunnis like Eissa and Hussein, even more pronounced given the power the Sunnis once yielded. The community, willingly or not, has been subjected to a string of supposed antidotes: an insurgency fought in Baghdad and the Sunni triangle north and west of the capital; a refusal to join the U.S.-backed political process in an attempt to foil it; and a boycott of the election in January in hopes Sunni abstention would deprive it of legitimacy.

The vote Saturday, in a way, was the latest attempt at empowerment.

Directors at five polling stations in Adhamiyah, housed in two schools, put turnout by midday at more than half of eligible voters, possibly far more. In interviews, nearly everyone voting Saturday said they had stayed away from the January election.

Perhaps the most important question Saturday was whether their turnout would bring them into a political process they have so far eschewed or, if the constitution is approved, deepen their alienation. Without exception, voters said they planned to cast ballots in elections in December to choose a new parliament.

"God willing, we have to secure the future of Iraq," said Wissam Faiz, a 22-year-old who voted no. "With a new election, we can elect a better government."

Could a better government exist with the occupation? he was asked.

Frowning, he shrugged. "Without an occupation," he said, somewhat ambiguously, "we would have never witnessed any of this."

An Iraqi raises his inked finger after casting his ballot in the constitutional referendum in the Sunni-dominated town of Fallujah.