It is not just the Muslim Brotherhood that is affected by this sea change. A welter of Islamic groups has emerged since the revolution, many of them previously living in shadows. One of the best known is the Islamic Group, the militant faction responsible for terrorist campaigns in the 1980s and 1990s that killed hundreds of police, soldiers, civilians and foreign tourists in Egypt. Although the group renounced violence in 1997, its name still strikes fear into many Egyptians, and the U.S. government still considers it a terrorist group.

The Islamic Group’s leaders agreed to meet with me for lunch at an outdoor cafe overlooking the Nile on a breezy spring afternoon. My fixer — a liberal Cairene woman who does not wear a headscarf — clutched my arm anxiously as we approached: these men, she reminded me, probably helped plan the assassination of Anwar Sadat in 1981. Yet after we sat down, she relaxed. Unlike many hard-line Islamists, they met her gaze, shook her hand and spoke to her respectfully. One by one, the men spoke emotionally about the revelatory effect the Tahrir protests had on them. Several repeated the same phrase: “It was like a holy scene, not a human scene.” The success of the protesters’ adamantly nonviolent tactics, they said, reaffirmed their belief that the Islamic Group had been wrong to use violence in the past, not just as a matter of principle but also because violence failed to achieve any of their goals. When I asked them if they were bitter about their experience in prison, where they had all served long terms, they referred again to Tahrir Square. “We have a belief that if someone has seen heaven, and he is asked if he has known misery, he says no,” said Osama Hafez, the group’s official spokesman. “When you see a thing like this, you forget everything you suffered.”

Hafez, who has spent 20 of his 53 years in prison, is a gaunt, elfin man with a white beard. During our talk, I asked about the protests that had broken out recently in southern Egypt after the Supreme Council appointed a Christian as governor of Qena Province. Some Egyptians took the protests as a troubling sign of religious intolerance. Hafez told me he responded to the protests with an offer: “Bring the Christian governor to Minya,” he said, referring to his home province. “You can have our governor, who is a Muslim.” I asked how the Islamic Group would feel about a Christian or a woman as president of Egypt. Hafez shrugged. “If the people vote for it, we are committed,” he said. “This is democracy.” This would be a remarkable turnabout for an organization whose members once branded moderate Muslims as heretics and labeled democracy an infidel concept. Sitting a few seats down from Hafez was the man who helped arrange the meeting, a musclebound 25-year-old named Gehad Saif. When I asked him if he was a member of the Islamic Group, he laughed raucously and said: “Me? I’m a liberal! I’m corrupt! I’m a D.J.!” He then explained that he had befriended Hassan Ammar, the man sitting next to him, in Tahrir Square. The two men fought together during the “Battle of the Camels” on Feb. 2, when the protesters fought back hundreds of armed Mubarak supporters, some of them on horses and camels. When Saif discovered that Ammar was a member of the Islamic Group, he was stunned. “I told him, ‘If you are part of the Islamic Group, then I want to meet the rest of them,’ ” Saif told me. “I thought these guys were terrorists, and I discovered I am totally wrong.”

One of the most common slogans in Tahrir Square during the revolution was “bread, freedom, social justice.” The order of those words was no accident. Many of the poorer protesters who filled the square before Mubarak’s fall were much less concerned about civil liberties or cross-sectarian harmony than about sheer physical need. A few days before Mubarak fell, I sat in the 26th-floor office of Naguib Sawiris, a telecom billionaire and one of the country’s richest men. He beckoned me to the window and pointed down at the buildings burned by angry protesters the week before, and the slum of Ramlet Boulaq, not far away. “That’s why they are doing this,” Sawiris told me. “They see the nice buildings we live in, and they have to live in this.” He had a point. About 40 percent of Egyptians live on the equivalent of $2 a day or less, and those numbers may well grow in the coming months. Since the revolution, Egypt’s economy has been mired in labor unrest. Tremors of anxiety in the country’s elite have begun to turn to panic.

“It is tragic,” I was told by Osama Leheta, an owner of one of Egypt’s oldest tourism companies. “Production in Egypt has come to a near-standstill. Foreign reserves are being depleted. Our currency is under extreme pressure. You could have millions of Egyptians with no food, and they will demolish everything in their path.”

Leheta, a tall, heavyset man of 64, did well under the old regime. He lives in a well-appointed villa about an hour northwest of Cairo, and his years in Britain have given him an accent so plummy it sounds like a Monty Python satire. But like so many Egyptians, he had visceral reasons to support the revolution. A few days after the first protests started, he was sitting at home one morning when a neighbor called to warn him that escaped prisoners were massing outside the compound, which is surrounded by gates. Leheta picked up one of his hunting rifles and set off toward the main gate with his five guard dogs. What he found there shocked him: hundreds of prisoners were streaming down the main road to Cairo, some of them in trucks they had commandeered. Others were walking, looking exhausted in the morning sun. Leheta and his neighbors fired into the air at first, to keep them away from the compound. Then they began detaining them and asking them what happened. The story that emerged was amazing. The men all said they were forced to leave the prison under threat of death. Some said they were starved for two days beforehand — presumably to make them more desperate when they got out. Mubarak’s government was deliberately terrorizing the country’s suburban upper class, in a clumsy effort to make the protests look bad.

The strategy backfired badly. When I first met Leheta a few days after those events, he was still angry. We sat in his vast, dimly lighted living room, which is decorated with Persian carpets and oil paintings. A fire burned softly in an antique grate. “Absolute power corrupts, and now these young people have stood up against an oppressive system,” Leheta told me. “It’s magnificent. We, the older generation, should be ashamed of ourselves. Every single one of us was cocooned in his little hole. We were afraid.”