CAIRO -- Activating its powerful clout and organization, the Muslim Brotherhood turned out vast crowds across Egypt Saturday in support of President Mohammed Morsi, a show of strength that suggested the challenges facing those who accuse the president of granting himself dictatorial powers one day ahead of a critical court decision.

The demonstrations coincided with Morsi’s announcement that he had signed off on a hurriedly drafted constitution and set Dec. 15 for a countrywide referendum on the document – even though the country’s constitutional court might rule Sunday that the Brotherhood-dominated constitutional assembly that wrote the document had been constituted illegally.

"This is the first time in our nation’s history an elected assembly drafts the constitution," Morsi declared. “I am calling for Egyptians to vote for the new constitution."

How the court will decide and whether there was any mechanism to enforce its decision if it overturns Morsi’s actions were unanswered questions, made more critical by the outpouring of support shown in Brotherhood rallies in Cairo and Alexandria, Egypt’s two largest cities, and other locations around the nation. There was no official accounting, but the turnout seemed to dwarf by many multiples the anti-Morsi protests held in recent days.

State television used split-screen technology to broadcast scenes from the massive pro-Morsi rallies as it showed the comparatively meager remnants of an anti-Morsi rally held Friday in Cairo’s Tahrir Square. The technique emphasized the difference in the size of the crowds the Brotherhood could turn out and those generated by the secularists, liberals and Christians who oppose Morsi’s most recent decree, when he exempted his declarations from court oversight.

The contrast was undeniable – and not just in numbers. The protests Saturday were filled with bearded Islamists and conservative women, many from poorer neighborhoods. Those who came to Tahrir on Friday clearly represented the nation’s upper class, with unveiled women and clean-shaven men.

Both sides claim to represent the demands of the “revolution,” Egyptian shorthand for the 18 days of protests nearly two years ago that ended when the Egyptian military pushed then President Hosni Mubarak from power and then governed the country itself until Morsi took the oath of office five months ago.

Developments since have only solidified the divide as this nation searches to define itself after decades of dictatorial rule that included the suppression of the Brotherhood. One man walking through the protests in support of Morsi on Saturday was overheard telling a friend, “Of course, Tahrir is full of people smoking and loose women. Thank God, we Muslims are united.”

Saturday’s protests were a reminder of the Brotherhood’s mastery of political organization.

At Cairo University, where the capital’s pro-Morsi rally was held, hundreds of thousands of people converged, brought from around the country by tour buses that lined the streets. Only 24 hours after the constitutional assembly hastily passed the draft constitution, supporters were already donning headbands that read “Yes to the constitution.”

Ralliers carried professionally made signs in support of Morsi, often with the same slogans. “We love you Morsi,” many read, and “The people support the president’s decisions.” Like clockwork, a pick up truck configured with speakers drove through the crowds, leading them in chants that denounced the Mubarak-appointed judges. “No No to remnants, Yes Yes to the Constitution,” the ralliers cried in a phrase that rhymes in Arabic.