Morsi's power grab in Egypt is no surprise, but there will be social and political costs

That Egyptian President Mohamed Morsi has granted himself wide-reaching powers and immunity from legal oversight is not a surprise.

Since winning June's presidential election – when he was welcomed into office by tens of thousands of Egyptians celebrating in the centre of the country's Arab Spring uprisings, Cairo's Tahrir Square – he has achieved little to address Egypt's economic woes or further Egypt's fledgling democracy. Instead, he has focused on shaping the Egyptian political and constitutional scene by consolidating power and authority in his own hands.

But what is surprising about this latest decree is the extent of the powers that he has invested in his presidential office. Morsi has effectively anointed himself supreme leader of Egypt, a strongman with absolute authority. Opposition figure Mohamed ElBaradei has accused him of becoming a "new pharaoh".

There is now no authority that can override any presidential decision that Morsi has made in the last year. Like his predecessors, Presidents Gamal Abdel Nasser, Anwar Sadat and Hosni Mubarak, Morsi has created an imperial presidency, a presidency that stands above the rule of law, civil society and power-sharing. It is a presidency that undermines the very foundation of the democratic process, the separation of powers, and the accountability of politicians – matters at the heart of the Arab and Egyptian "revolution".

The Muslim Brotherhood, the Islamist party of which Morsi is leader, praised Morsi's move, describing it as necessary to "protect the revolution and achieve justice". The language takes us back to the revolutionary period of the 1950s and 1960s, as opposed to the post-Arab Spring constitutional moment in Egypt.

Morsi's decree for a retrial of the ousted Mubarak and other ex-regime officials accused of killing protesters during the demonstrations last year appears to have been motivated by a desire to appease public anger over the impunity they have been allowed so far. Morsi's supporters would like us to believe that he needed extraordinary powers to speed up these trials, but immunity from prosecution and accountability for himself has little to do with justice. His power grab is bound to only intensify social and political struggles in Egypt, as yesterday's protests show. It has poured gasoline on an already raging fire.

The bottom line is: critics and detractors have underestimated Morsi. They have underestimated his shrewdness, his determination, and his ability to concentrate his powers. When, a few months ago, he isolated Egypt's old military guard by promoting young officers who represent a new generation, many were surprised that in one stroke he was able to get rid of Field Marshal Mohamed Hussein Tantawi and his army commanders.

Now, Morsi has made his decisive move at a critical moment – just after brokering the Israel-Gaza ceasefire, and after Barack Obama praised him for his precision, discipline and pragmatism during the negotiations.

After the last 48 hours, Morsi's critics will underestimate him again at their own peril. What is certain is that there will be social and political costs for Morsi's move, raising the spectre of further political instability which Egypt can ill afford.

When he was elected, Morsi declared: "I have no rights, only responsibilities... If I do not deliver, do not obey me." Now, he may find his words come back to haunt him.

Fawaz A Gerges is a professor of international relations at the London School of Economics where he directs the Middle East Centre. His most recent book is "Obama and the Middle East: The End of America's Moment?"