"It looks like it's over for the Brotherhood," said Sameh Eid, a former member who has maintained contact with the group. "Brotherhood families are grieving over their dead or busy trying to see how they can visit loved ones in detention or others who are injured. The animosity on the streets is exhausting them and allies are abandoning them."
Founded in 1928, the group has spent most of its 85-year existence on the sidelines, outlawed, harshly treated and demonized by successive regimes. The June 2012 election of one of its longtime leaders, Mohammed Morsi, in Egypt's first free presidential vote was the pinnacle of its newfound power. With its own man in the land's highest office and its members dominating the legislature, the Brotherhood looked invincible.
It did not last long, however. The military toppled Morsi in a July 3 coup after barely a year in office, dealing the Brotherhood a devastating blow.
Shortly before his ouster, Morsi's supporters set up two sit-in camps at strategic squares on opposite ends of Cairo. The camps soon became a springboard for daily demonstrations that crippled much of the city.
After security forces cleared the two camps last week, leaving hundreds dead, enraged Brotherhood supporters attacked police stations and government buildings, as well as churches, homes and businesses of minority Christians nationwide. It was an attempt to spread chaos and force the police to vanish as they did in the face of the mass protests of the 2011 uprising against autocrat Hosni Mubarak.
It was a risky gamble that cost the Brotherhood dearly in popularity and lives and gave the military-backed authorities cover to press ahead with a campaign to decimate the group.
At the same time, state media unleashed a propaganda blitz that has portrayed the group as a terrorist organization that must be banned.
Hundreds of Brotherhood leaders and supporters have been detained in the crackdown, crippling the group's command structure and demoralizing loyalists and sympathizers with the arrest of some of its most iconic figures, including 70-year-old supreme leader Mohammed Badie.
Badie and his powerful deputy are to face trial later this month for their alleged complicity in the killing of protesters outside the group's national headquarters in Cairo. Morsi, who has been detained at an undisclosed location since his ouster, is accused of conspiring with the militant Palestinian Hamas group to escape from prison during the 2011 uprising as well as complicity in the killing and torture of protesters outside his Cairo palace in December.
In addition to the arrests, a campaign is in full swing to "cleanse" ministries, government departments and state media of Brotherhood supporters.
Already, the effects of the crackdown are apparent.
Pro-Morsi demonstrations in Cairo and elsewhere in Egypt have diminished since last week's deadly clashes. Insiders say supporters are reluctant to take to the streets after the government authorized the use of deadly force against protesters last week.
Still, the Brotherhood's history shows the group's resilience in the face of past crackdowns lying low, regrouping, then re-emerging to steadily regain influence.