There is a legend about how Alexander the Great solved an intractable problem he came across during his conquests. An ox cart in the ancient kingdom of Phrygia (in today's Anatolia) had been attached by a knot to a post by Zeus. The man who could untie the knot, an oracle had prophesied, would have the approval of the gods to rule. When Alexander arrived in Phrygia, like previous would-be conquerors, he struggled to untie it. His solution, ultimately, was to draw his sword and cut the rope.

This parable is alternatively interpreted as being about ingenuity and thinking outside the box, or as an argument that might makes right. This is also the debate now raging in Egypt after President Mohammed Morsi, in an extraordinary executive decree, took the right to rule without constraints.

Mr Morsi and his supporters - mostly Islamists - argue that the step was a necessary solution given an intractable problem: Egypt's transition has languished far too long, hostage to politicking and the whims of an unreformed judiciary hostile to the new president.

The courts' power to cancel the results of elections, like June's disbanding of the lower house of parliament, or possibly dissolve the assembly now drafting a new constitution, was too disruptive to restoring normality and order in a country that sorely needs to move forward.

The presidential decree announced on Thursday evening also offered some welcome moves. The deadline for the writing of the constitution has been extended by two months, offering an opportunity for the third of the constituent assembly's members who walked out last week to return and negotiate. Mr Morsi has also appointed a new public prosecutor, replacing an unpopular official he had tried to sack last month, and ordered retrials in cases of police violence in the 2011 uprising, including the case of his predecessor, Hosni Mubarak.

The decree was preceded by cryptic leaks to the press that Mr Morsi would be taking bold measures. The Muslim Brotherhood dispatched its cadres to hold a demonstration at the Cairo High Court - a stand-in for the judiciary - and rumours spiralled as to what Mr Morsi might do. In the local and international press, praise was lavished on him for his handling of the Gaza crisis and his reconciliation with a US president who only two months ago was unwilling to describe the new Egypt as an ally.

Mr Morsi's administration may have been in trouble over its handling of various issues, from the constitutional debate to transport disasters, but personally Mr Morsi was on top of the world. This, it was expected, would have been his chance to pivot from a foreign-policy success and break the deadlock in Egypt's domestic politics.

Or so he thought.

The premise of the president's plan was sound. There was a need for him to get more involved in the constitutional debate and address some of the opposition's concerns (which had, among other things, asked for more time.) Several days of clashes in downtown Cairo had become an embarrassing reminder of the state of Egypt's transition and of the desire for justice for those who paid the ultimate price for overthrowing the Mubarak regime.

Dismissing the public prosecutor and preventing the dissolution of either the upper house of parliament or the constituent assembly were risky moves that would certainly face opposition, but mostly in terms of a face-off with judges - which was taking place anyway.

Where Mr Morsi overstepped is that he formally gave himself open-ended powers to make decrees that are immune from judicial oversight (therefore barring any legal recourse against them), giving himself licence to do pretty much anything else he pleases in the name of national security. He claims that this is a temporary measure to ensure that the country reaches its end goal - a new constitution and a new elected parliament - as quickly as possible. To achieve this, he is taking absolute power for three months or so, and promising to use it sparingly.

Were Mr Morsi a beloved national leader of the stature of a Nelson Mandela, he might have pulled it off. But he is the backup candidate of an organisation - the Muslim Brotherhood - mistrusted by many of his countrymen. He was elected (narrowly) by a coalition brought together by the fact that his opponent was worse. And he made this decision at a time of unprecedented polarisation - over the constitution and religion's role within it, over the performance of the cabinet, and indeed over the poor excuse for a transitional framework to democracy that the country inherited from 16 months of disastrous military rule. Mr Morsi's political capital is simply not as plentiful as he seems to believe, as the furious reaction by opposition leaders and protesters on Friday showed.

The question now is what next. Mr Morsi and his supporters say the move is necessary, and the opposition is being irresponsible, bent on sabotaging anything he does out of anti-Islamist spite. That is partly true: there are many, from conservatives nostalgic of the Mubarak era to angry revolutionaries, who simply cannot stomach that Mr Morsi is president and his Muslim Brotherhood are the dominant political power. Opposition groups, the revolutionary movement and civil society feel cheated by the Islamists' majoritarian view of democracy, and they are also right to be worried about the Islamists' views on the application of Sharia and their lack of enthusiasm for civil liberties.

The central problem in Egyptian politics today is trust, or the absence thereof - and Mr Morsi has not invested much time in creating more of it since elected. This new wave of protests is the price he is paying for his negligence.

Cutting the Gordian knot, ultimately, is cheating. Getting away with it depends on being perceived as either wise or powerful. The next few weeks will test Mr Morsi on both counts.

Issandr El Amrani is an independent journalist based in Cairo who blogs at arabist.net

On Twitter: @arabist