Sporadic violence flared across much of the country on the first day of the voting, leaving 11 dead, with protesters burning tires and pelting police with rocks and firebombs creating just enough tension to keep many voters at home Tuesday.
The constitutional vote, which ends Wednesday evening, is a key milestone in a military-backed political roadmap toward new elections for a president and a parliament after the July 3 coup that left the nation sharply divided between Muslim Brotherhood supporters in one camp, and the military and security forces in another, backed by a large segment of the population that is yearning for stability after three years of deadly turmoil and economic woes.
Still, the vote so far has yielded telling signs that the national sentiment is overwhelmingly behind military chief Gen. Abdel-Fattah el-Sissi, whose possible presidential run later this year has grown more likely by the day.
That a career army officer might be Egypt's next president has raised questions about the future of democracy here, but it also speaks to the fatigue felt by most Egyptians after all the upheaval that engulfed the country since the 2011 ouster of the longtime autocratic ruler Hosni Mubarak.
The vote is taking place in a climate of fear and paranoia, with authorities, the mostly pro-military media and a significant number of Egyptians showing little or no tolerance for dissent. Campaigning for a "no'' vote risked arrest by the police. Egyptians who have voiced their opposition to the charter, or even just parts of it, are quickly labeled as traitors.
Nearly 400,000 soldiers and policemen fanned out across the nation of some 90 million people on Tuesday to protect voters against possible attacks by militants loyal to ousted President Mohammed Morsi, who hails from the Brotherhood. Military helicopters hovered over Cairo and other major cities, while grim-faced, black-clad masked commandos stood guard outside polling centers.
An explosion struck a Cairo courthouse before polls opened, damaging its facade and shattering windows in nearby buildings but causing no casualties in the densely populated Cairo neighborhood of Imbaba, a Brotherhood stronghold.
The Health Ministry said 11 people were killed and 28 were wounded in clashes between pro-Morsi protesters and security forces _ a relatively low number of fatalities, well below the grim predictions in the run-up to the ballot.
The Brotherhood, now branded a terrorist group, had called for a boycott and vowed mass demonstrations to disrupt the vote. But Tuesday's widely scattered protests numbered no more than 200-300 people each, mostly teenagers and men in their early 20s, many armed with rocks, firebombs and bird shot.
The referendum is the sixth nationwide vote since Mubarak was toppled in 2011, with the five others widely considered the freest ever in Egypt, including the June 2012 election won by Morsi.
But this vote was tainted by criticism that many of the freedoms won during the revolution have vanished amid a fierce crackdown on Morsi's Brotherhood and a smear campaign against some of the activists who engineered the 2011 uprising but remained steadfastly opposed to the military's involvement in politics.
The new charter, drafted by a committee dominated by liberals appointed by the military-backed government, would ban political parties based on religion, give women equal rights and protect the status of minority Christians. It also gives the military special status by allowing it to select its own candidate for the job of defense minister for the next eight years and empowering it to bring civilians before military tribunals in certain cases.
The charter is a heavily amended version of a constitution written by Morsi's Islamist allies and ratified in December 2012 with some 64 percent of the vote, but with a nationwide turnout of just over 30 percent.
The current government is looking for a bigger "yes'' majority and larger turnout to win undisputed legitimacy and perhaps a popular mandate for el-Sissi to run for president. El-Sissi has yet to say outright whether he plans to seek the nation's highest office, but his candidacy appears increasingly likely every day.
Illustrating the high stakes, the government and the overwhelmingly pro-military media have portrayed the balloting as key to the nation's security and stability. Hundreds of thousands of fliers, posters, banners and billboards have urged Egyptians to vote "yes,'' while anyone displaying posters calling for a "no'' vote risked arrest.