Some protesters now demand Morsi be tried for killing protesters just as Mubarak before him was. Mubarak was convicted in June and sentenced to life in prison for failing to prevent the killing of some 900 protesters during the 2011 uprising against him. On appeal, a court has ordered his retrial.
"This man (Morsi) is responsible for the killings but no one is trying him. Is he above the law?" said Ashraf Helmi, a protester in Port Said.
In Cairo, protester Mabrouk Hassan Abu-Zeid, 26, said he expected things to get so much worse.
"A failed state? I see much more than that on the horizon. There could be a revolution by the hungry," he said near Tahrir Square as fellow protesters hurled stones at police firing tear gas.
In comments to cadets on Tuesday, the army chief and defense minister, Gen. Abdel-Fattah el-Sissi, made what was seen by many as an implicit warning to Morsi that he must do something.
He said if political forces can't end their difference over how to run the country, it "could lead to the collapse of the state and threaten future generations."
There was no threat, implicit or otherwise, of a coup in the comments by el-Sissi, who many in Egypt suspected to have made a deal with Morsi when the president appointed him in August.
But military analyst and retired army general Hossam Sweilam said they conveyed the "gravity" of the situation and the possibility that it could a reach point where the armed forces could no longer stand by without intervening.
"Gen. el-Sissi understands the Brotherhood well and they will not be able to play him," he said. "Even if he was loyal to them at some point in the past, he is aware now that he is being closely watched by his own men."
Egypt's military saw its reputation tainted in the nearly 17 months it spent at the helm following Mubarak's ouster, with rights activists blaming the generals for mismanaging the transition to democratic rule and widespread human rights abuses. The top brass handed over power to Morsi following his June election, but tried to keep many of his powers.
Morsi struck back in August, forcing out the army chief and replacing him with el-Sissi.
The military remains widely popular and revered as the nation's protector. Some privately speak of their wish to see the military rid them of Morsi, his Brotherhood and other Islamists, provided the army's rule is short.
Now Salafis appear less willing to stand by Morsi, who has relied heavily on their support. Salafis won nearly 25 percent of parliament's seats in elections held in late 2011 and early 2012, in which the Brotherhood won around 50 percent.
After his talks with the Salvation Front on Wednesday, al-Nour Party leader Younis Makhyoun told reporters that Egypt must not be left in the hands of "a single faction," a thinly veiled reference to Morsi and his Brotherhood.
"There must be a real partnership," he added.
It is not clear at this stage how durable any cooperation would be between the Front and al-Nour, which are on the opposite ends of the political spectrum.
Al-Nour and other Salafis were key in ensuring passage of the constitution, which has a distinct Islamist slant and which liberals vehemently oppose. Salafis also push relentlessly for strict implementation of Shariah in Egypt, a mainly Muslim nation of 85 million people, and take a hardline stand on the rights of women and minority Christians.
But Salafis, too, worry about domination by the Brotherhood.
The Brotherhood is so confident in its own strength it thinks it doesn't need anyone's support, said Hamada Nassar, a spokesman for the political arm of the onetime jihadist Gamaa Islamiya group.
"The popularity of the Muslim Brotherhood in the street is eroding," he said, "but its leaders think that if they nominate a rock to run for parliament, it will win."