There have been five parties controlling Iraq's executive branch exclusively for the last few year even though they control only a minority of seats in the Iraqi parliament. The five parties are the two Kurdish parties (puk and kdp), two shiites parties (Dawa of Al-Maliki and ISCI), and one Sunni party (the Islamic party). These five parties combined control a little bit more than 100 seats out of the Iraqi parliament's 275 seats, putting them well below the 138 seats required for a quorum.
Al-Maliki has gradually broken his ties with the other 4 parties during the last few months, and that was one of the reasons he managed to survive the provincial elections, unlike the other four who lost miserably.
There are 3 major reasons for the growing split between Maliki and the other 4 parties
1- Demographic cleansing: Al-Maliki is againt partitioning Iraq now. The gang of 4 have been following and promoting a separatist agenda aimed at creating sectarian/ethnic/religious regions that are self governed instead of having a strong central government in Baghdad running the country. The gang of 4 have been supporting the cleansing campaigns directly and indirectly for years. Al-Maliki's recent attempts to reverse ethnic and sectarian cleansing and remove all walls in Baghdad were faced by fierce criticism by the gang of four. Following last week's organized attacks in Baghdad, Hoshya Zibari (a kurdish separatist who happened to be Iraq's minister of foreign affairs) claimed the reason behind the attacks is Al-Maliki's plan to remove the partitioning walls!
2- Central government vs. regional powers: Al-Maliki is now for keeping and even increasing the powers of the central government. Mainly because he's fighting for his own position's authorities, and because he's catering to the Iraqi public opinion that, according to numerous polls, favors a model where the central government runs a united and sovereign nation.
3- Ending foreign intervention(s): Al-Maliki's support for a plan where ALL U.S. troops must leave Iraq has been against the gang of four's interests. They realize that the U.S. is there protecting them and supporting their weak and unpopular regime, and more importantly, the US is fighting their fight against other Iraqis.
The gang of 4 will try their best, in collaboration with other separatists around Iraq, to delay or cancel the upcoming legislative elections because they know that they're going to loose this time, big time. They'll end up being a small minority in both the legislative and executive branches. ISCI, with Al-Hakim Dying and their supporters shrinking, will try their best to reignite the sunni/shiite divisions and to try to pressure the Sadrists (through Iran's influence) to run with them in one coalition. I think such a coalition will most likely include some token Sunnis, kurds, and Christians and I think it will most likely collapse very soon after. The PUK/KDP will most likely quit all their positions in the central government and go back to Kurdistan to start a war with Baghdad and invade Kirkuk, or they might continue their participation if they have any hope they can destroy the central government from within. The Islamic party will continue its lame and underground coordination and collaboration with the other members of the gang.
There is a lot of violence coming ahead, but this does not mean in anyway the US occupation should last for an extra day. All what Iraqi is living now and will be living in the next months and years is because of the US intervention that has destroyed the nation and took the side of some sunnis, shiites and kurds against other sunnis and shiites and kurds. Iraq is far from being a stable and peaceful country, and there no surge that can fix it. There is nothing that the US can do to fix the situation other than leaving Iraq completely and stopping all forms of intervention in Iraq's domestic issues.