My basic take on all the politics unfolding in Egypt is, Liberal and Progressives 'screwed' it in the first place and they are now trying to rectify the situation by opposing President' Morsi's decree. What is further shameful is, though Morsi 'power grab' is indeed bad; these progressives are dependent on Mubarak era Judges to get themselves out of this mess.
Intense 'infighting, rivalry and inability to forge leadership'; all that resulted in Egyptian Progressives conceding the ground to Brotherhood and other Islamic Parties in the Assembly election at the start of the year. Were these Progressives to have majority in that election, for sure they would have backed Constitution Draft today! Now that it is drafted by Brotherhood and Islamist Parties; it no longer becomes 'representative of all of Egypt'; as if all those votes to Brotherhood and Islamist Parties in the assembly election and votes to Morsi do not count! Sour grapes.
Fragmentation of votes among Islamist Parties occurred too, but it was not as bad as like Progressives and Liberals. Besides, Muslim Brotherhood has been the dominant player all along.
All this reminds me politics in India. Indian Opposition Parties from Right (BJP) to Left (Communists) with Socialists dominating in the middle (Janata Party and their brethren); tried couple of times to rally against Indian National Congress; but failed miserably because of intense 'infighting' among themselves. Despite being on the right side of the History, they could not achieve much. Same seems to be the case with Egyptian Progressives and Liberals, prominent leader among them being ElBaradie - these folks blew when they needed to be united. Let us not forget that Brotherhood and Islamist constitution will not be any progressive and indeed will be want of 'inclusive of all Egyptians'. But the crucial moment - Assembly Elections - to make the difference is lost and Egyptian Progressives will have to start the long march of correcting all these imbalances over a protracted battle lasting over multiple decades.
I do not justify many non-liberal strains of Brotherhood and their kind of politics. Again comparing with Indian situation, RSS continued it's ultra-conservative views for long; but that did not hinder BJP (political organ of RSS) from adopting Modernist views. So as Muslim Brotherhood adopts to governance, who knows even they may tamper their views. After all improving miserable lives of common Egyptians is the dire need of the hour and so long as that gets addressed; Muslim Brotherhood and Islamic Parties would have time on hand and room to maneuver in diminishing stridency of their political views.