CAIRO (AP) -- In abstract terms, Sunday's planned protests aimed at forcing out Islamist President Mohammed Morsi would seem to violate a basic principle of democracy: If a fair vote is conducted, even if the majority is slim or the turnout modest, all must respect the results. Otherwise it's political chaos.
Morsi's Islamist supporters have been angrily making that argument for weeks, accusing loyalists of the ousted autocrat Hosni Mubarak of being behind the campaign against the president and of aiming to thwart democracy, one of the main aspirations of the 2011 revolution that removed him.
But the organizers of Sunday's protests insist he has lost legitimacy through what they call a series of power grabs, missteps and poor decisions, and that Morsi, his Muslim Brotherhood and their Islamist allies are using victories -- at times narrow -- scored in elections during a still nascent and transitioning democracy to control it completely for themselves.
They argue the Islamists unfairly set the rules of the game by pushing through a new constitution without consensus, broke the rules with decrees that for a period put Morsi above oversight, ran roughshod over the courts and attacked previous anti-Morsi protesters. In their eyes, he is allowing one faction -- Islamists ranging from the Brotherhood to ultraconservative Salfis and more radical groups -- to monopolize power and take the country down a more Islamist and sectarian path beyond any election mandate.
They also say they can show millions have lost faith in Morsi because of mismanagement and will bring gigantic crowds into the streets Sunday to stay for as long as it takes.
"Leave voluntarily because the nation can no longer suffer another day with you in an office tainted by blood and hatred," Tamarod, the youth movement fueling the protest campaign, proclaimed in a statement. It says it has collected at least 15 million signatures of Egyptians who want Morsi to step down -- around 2 million more than the number of votes Morsi received when he won last year's presidential election with almost 52 percent of the vote.
The Freedom and Justice party, the political arm of Morsi's Brotherhood, said on its official Twitter account: "Egyptian opposition flouts principles of democracy, mobilizes for violence."
"We're talking about the legitimacy that the Egyptian people came out to confirm in repeated elections and finally in choosing Mohammed Morsi," Abdel-Nasser Ali, a Brotherhood figure in Alexandria and head of the local teachers union, told a Brotherhood-organized conference Tuesday. "We won't let anyone leap over the ballot box by force. The people's will is the foundation."
The legitimacy question may seem abstract, but it hangs over Sunday's protests, set on the anniversary of Morsi's 2012 inauguration.
Confident Morsi will fall, Tamarod and other opposition groups have come up with a road map for what's next, involving an interim technocrat government, the suspension of the largely Islamist-drafted constitution while it is rewritten by an expert panel, then new elections in six months.
But if the protest campaign does succeed, many Islamists could reject the legitimacy of any post-Morsi system.
That raises the potential for a violent backlash, particularly since -- apart from democracy questions -- prominent hard-liners have railed against the campaign as a conspiracy to thwart the "Islamist project" of turning Egypt into a state ruled by Shariah law.
If the opposition does succeed in bringing overwhelming numbers into the street yet Morsi remains in place, it raises the question of how he can effectively rule.
"We have said all along that we have no problem with (Tamarod) as long as it's peaceful, but not for the movement to become a mechanism to impose its own vision," Yasser Mehrez, a spokesman for the Muslim Brotherhood, told The Associated Press on Wednesday. "This is going to lead to chaos and no president will in the future be able to stay in power for more than a month."
These are some of the issues that have fueled controversy over Morsi the past year.
Morsi's opponents say he has repeatedly tried to defy the judiciary, which is the sole branch of the government not dominated by Islamists, though there are Brotherhood backers among the judges. Morsi's backers have said the courts are controlled by Mubarak loyalists trying to foil his agenda.
In November, Morsi issued a constitutional declaration that banned the courts from reviewing any of his decisions. He also barred them from ruling on the legitimacy of the Islamist-dominated constituent assembly drafting the new constitution or the upper house of parliament, which judges were considering whether to dissolve.