The result: The Brotherhood (known as the Ikhwan) is by far the best-organized political movement in the barren Egyptian political landscape. Having renounced violence decades ago - the blogosphere notwithstanding, the Ikhwan did not kill President Anwar Sadat - the Brothers are poised to take advantage of Egypt's new democratic opening, form a political party, and set up a satellite-TV network. Although their strength probably does not exceed 15 to 20 percent of the population, their organizational skills could gain them a hefty chunk of parliamentary seats.
Yet Egypt is not Iran. Countervailing forces should, at least for the foreseeable future, keep Egyptian Islamists in check.
First, the youths who led Egypt's 18-day revolution are seeking democracy, not an Islamic state. "The silent majority in Tahrir Square, when [it] finally found a voice, none of them showed religious leaning or carried Muslim Brotherhood slogans," I was told by Khaled Sayed, an intense young leftist and key leader in a coalition of youth groups. We met in the Groppi cafe, a faded remnant of Egypt's past, with Art Deco panels and chandeliers, that has become a meeting place for revolutionary youths.
A contingent of young Muslim Brothers did play a key role during the revolt, but the Ikhwan as a whole was slow to support the rebellion. Most Tahrir Square activists don't want to see their revolution hijacked by an Islamist group.
Second, the Ikhwan must prove itself to a population that has suddenly become politically conscious. "When only 20 percent of the population was politically active, the Muslim Brotherhood had a great chance," said the well-known young blogger Ahmad Badawi. "When the door is open to more activism, and when maybe 70 percent of the population is active, the Ikhwan can be balanced by other forces."
Badawi says new political parties, plus the 10 percent of the population that is Coptic Christian, will offset the Ikhwan's clout. But he says he fears the six-month schedule set by the army for new elections will leave too little time for these parties to get off the ground.
Of course, the most critical balancing factor will be the army. Many Egyptians, drawing parallels with Turkey, believe their military will keep the Islamists under control.
Much will also depend on how the Muslim Brothers play their cards in this new environment. A 2007 draft of the Ikhwan's platform set off alarm bells when it called for banning women and Copts from the presidency and for a body of clerics to advise parliament on the Islamic validity of legislation. This alienated many Egyptians.
I visited the Ikhwan's shabby but bustling headquarters in Cairo's Manial district to see the deputy chairman of the Brotherhood, Rashad Mohamed al-Bayoumi. His avuncular appearance belies the 18 years he spent in prison. He stated: "We will not seek the presidency, and we will not seek a majority of seats" in parliament. So the Ikhwan is trying to calm fears that it seeks power.
Asked whether he wants an Islamic state, Bayoumi replied: "An Iran-type government can't exist here, because it is a civil state." But this rhetoric didn't sit well with his insistence that "if we won control of government, no Christian or woman could serve as president" or that liquor should be forbidden except in "areas used by foreigners."
Clearly, the Ikhwan is still trying to define its platform in this new environment, where it can now operate openly but can't legally form a "religious" party.
Younger Brothers who took part in the Tahrir Square revolt and are Facebook-savvy use different language. "We want a civil state that doesn't differentiate between people based on religion," said Mohammad Abbas, 25, a handsome, beardless youth who battled in the square. "We want a state where freedom of assembly and speech are guaranteed."
Will the more modern Ikhwan youths pull their elders toward an Islamic politics more compatible with democracy? Perhaps. Yet their language does not convince non-Islamist Egyptians of their benign intentions.
The best way to balance the Ikhwan is for Egyptians to build new parties that appeal to Egypt's majority, leaving the Islamists to play a minority role. But that hope comes with a caveat: It assumes the army will always be there in the background to make certain nothing goes wrong.
Trudy Rubin is an international affairs columnist for The Philadalphia Inquirer. She travels extensively several times a year in the Middle East, Afghanistan and other places of strategic interest to the U.S. Writer to her at email@example.com.