CAIRO — Egypt's most powerful and proscribed opposition movement, the Muslim Brotherhood, has decided that it will not participate in an antigovernment demonstration this week for a curious reason: The protest conflicts with a national holiday honoring the police.

"We should all be celebrating together," said Essam el-Erian, a senior member of the group, offering an explanation that seemed more in line with government thinking than that of an outlawed Islamist organization, whose members are often jailed.

That type of calculation, intended to avoid a direct confrontation with the state, is helping build momentum, many here say, for a political evolution — in Egypt and around the region — where calls for change are less and less linked to a particular ideology like Islamism. Instead, analysts and activists say the forces that brought people to the streets in Tunisia and excited passions across the Middle East are far more fundamental and unifying: concrete demands to end government corruption, institute the rule of law and ease economic suffering.

This is a relatively nascent development in a society like Egypt, which has been depoliticized over the past three decades of President Hosni Mubarak's one party, authoritarian rule, experts said. But the shift seems to be striking fear in the country's leadership, which has successfully pacified opposition by oppressing those it cannot co-opt, but which remains anxious about the prospect of a popular revolt, political analysts and activists said.

"Ideology now has taken a back seat until we can get rid of this nightmare confronting everyone," said Megahed Melligi, 43, a longtime member of the Muslim Brotherhood in Egypt who said he quit the group three years ago out of frustration. "This nightmare is the ruling party and the current regime. This is everyone's nightmare."

In 1979, the Iranian revolution introduced the Muslim world to the force of political Islam, which frightened entrenched leaders, as well as the West. That ideology still has a powerful hold on people's imaginations across the region, which continues to feed fighters to jihadist movements. But like Arabism and socialism before it, the political Islam of Ayatollah Ruhollah Khomeini of Iran and the radicalized ideology of al-Qaida and Osama bin Laden have failed to deliver in practical ways for the people across the Middle East who live in bastions of autocratic rule.

That failure — and now the unexpected success of Tunisians in bringing down their government — appears to be at the heart of a political recalculation among some about how best to effect change in the Arab world. The Tunisians were joined together by anger at oppression and corruption rather than any overarching philosophy.

Even before the Tunisian revolution, Egyptian activists from the both sides of the political spectrum had been increasingly pointing not to Iran's revolution as a model, but to Turkey's method of governance, where an Islamic party runs a modern, democratic and accountable state.

One of the groups planning to demonstrate on Police Day, which calls itself the April 6th Youth Movement, emphasizes its absence of ideology in its description on its website: "Nothing brings us together except our love for this country and the desire to reform it."

Abdel-Halim Qandil, a leader in another protest movement, which calls itself Kifaya, or Enough, said: "People in the West are talking about the religious 'threat.' They don't understand what kind of hell we are in right now. The country is congested and people are unable to confront the regime."

While Tunisia is a far more secularized society than other Arab states, its citizens' demands are the same as those being heard in many nations in the region, even those rich in oil wealth like Kuwait. There are many places thick with disillusionment over the failure of formal political parties and organizations, like the Muslim Brotherhood's political arm in Jordan and the traditional opposition parties in Egypt, which have failed to deliver change.

"This is exactly what the Tunisian case shows us," said Emad Shahin an Egyptian scholar at the Kroc Institute for International Peace Studies at the University of Notre Dame. "It's not the age of ideology anymore. This concern about ideology and certain political orientations of Islamism is really over. There are more pressing issues that all the players, including the Islamists, are interested in now and have to deal with."

This is not to say that formal organizations, especially the Muslim Brotherhood in Egypt, have lost their influence or their followers. Although the brotherhood has been outlawed by the state, it has a broad network of social services around the country, which the government tolerates, and an ability to bring armies of supporters out — if it chooses to.

But the movement's leaders are from a generation that focuses foremost on survival, which means avoiding confrontation with the state, political analysts said. And that position which has alienated some of its younger members.

"The ones who are there and working without calculating every little thing are the youth," Melligi said. "They have nothing to lose. They don't have headquarters and organizational structures for the government to target."

Another unexpected element thrust into the region by the rush of events in Tunisia has been the emergence of self-immolation as a symbol of the non-ideological political dynamics. The revolution in Tunisia started with just such a desperate act — when a young food vendor burned himself to death after the police confiscated his wares and humiliated him. The practice has since spread across northern Africa and the Middle East. A man in Saudi Arabia died after self-immolating on Saturday in the first case of its kind in the country. In Egypt, at least five men have set themselves ablaze, or tried to.

The government seems keenly aware of the power that the image of a person engulfed in flames carries, and its potential to accomplish what the mainstream opposition has been unable to: transforming widespread discontent into a collective call for political change. The government has ordered gas stations not to sell to individuals who are not in vehicles, instructed prayer leaders to remind worshipers that suicide is a sin, and stationed security agents, who were armed with fire extinguishers, outside government offices.

The first Egyptian to burn himself last week did so in front of government offices in the center of Cairo, pouring a gallon of gasoline over his head and lighting a match. He most likely would have died had security agents not used a fire extinguisher on him.

The story of the Egyptian man, Abdo Abdel-Moneim Hamadah, is strikingly similar to that of Mohamed Bouazizi, the young food vendor from Tunisia who killed himself. Hamadah had a small sandwich shop in Ismailia. The government bureaucracy suddenly denied him access to a monthly allowance of cheap, state-subsidized bread. After he set himself on fire, the government-controlled media said he was suicidal over that issue.

A relative said, however, that his protest was not about bread but dignity, the same intangible that drove Bouazizi to light himself on fire and that the governments here and around the region have yet to redress. The relative said Hamadah snapped after a government official agreed to give him back the bread, not because he was entitled to it, but as charity.

"They spoke to him like he was a beggar," said the relative who spoke anonymously for fear of government retribution. After Hamadah burned himself, the relative said, the government turned over the cheap bread.

"He got his rights," the relative said. That, he said, was all Hamadah had been seeking.