"I have dedicated myself and my life for democracy and freedom," he told hundreds of supporters outside the presidential palace in Cairo. "The steps I took are meant to achieve political and social stability."
The chair of Egypt's Cabinet, Mohamed Refaa al-Tahtawi, brushed back criticisms that Morsy had made an undemocratic power grab, saying the opposite is true and that Morsy "is not really trying to monopolize power."
"He is trying to have strong pillars for a steady progress toward democracy," al-Tahtawi said. "A dictator would not try to have an elected parliament as soon as possible."
The Cabinet chief added, "I assure you that in the coming days, the opposition will fade away and calm down."
But that sentiment was not shared by everyone.
Tensions were brewing days before the president's moves; protesters have been in Tahrir Square since Monday.
The anger has been directed at Morsy and the Islamist movement of which he is a member. The Muslim Brotherhood was banned under Mubarak but has since risen exponentially in stature. There has also been growing turmoil about the constitutional panel, pitting conservatives who want Egypt to be governed by Islam's Sharia law against moderates and liberals pushing for it to ensure basic freedoms, including for women.
On Friday in Tahrir Square, thousands had Morsy in mind as they chanted, "Leave, leave," and "The people want to topple the regime," the signature phrase of the Arab Spring uprisings, cried out from Tunisia to Egypt and Syria.
Nearby, in front of Egypt's parliament building, thousands of protesters threw rocks as police used their vehicles and tear gas to keep the crowd contained.
A Cairo doctor said Saturday that a day earlier he treated five patients who had been wounded by shot pellets. But most of the injuries Dr. Mahmoud Said handled at Mounira Hospital were cuts resulting from hurled stones.
The top floor of an eight-story apartment building caught on fire Friday night, a blaze protesters blamed on a police tear gas canister tossed at demonstrators who were on top of the building earlier in the day.
About 215 kilometers (130 miles) north in Alexandria, protesters on Friday stormed the headquarters of the Muslim Brotherhood's political wing and set it on fire, said Ahmed Sobea, a spokesman for the Freedom and Justice Party.
Calling for calm and dialogue, the U.S. State Department expressed concern Friday about the developments, saying, "One of the aspirations of the revolution was to ensure that power would not be overly concentrated in the hands of any one person or institution."
Thus far, authorities have arrested 210 protesters, 85 of whom are charged with destroying public property, thuggery and attacking security forces, the Interior Ministry said, according to state TV. Some 44 of those arrested are juveniles who are now back with their families.
"My worry ... is that the while situation will turn ugly, will turn violent if Morsy doesn't rescind (his) decisions (and) engage in dialogue with the rest of the country," ElBaradei said, adding he had met with Morsy a week ago and felt blindsided by his moves.