Abu Aardvark points out that Hamas Iraq results from a split with the 1920 Revolution Brigades, but that it hasn't been seen much since. It is apparently close to the ideology of the Muslim Brotherhood, and it opposes the sectarian drift of some organisations. The faction of Ansar al-Sunna that is participating (the Legitimate Committee of Ansar al-Sunna) is reported by the Guardian to have broken with the main group over sectarianism and the strategy of suicide attacks:
"We wanted to unite with other resistance forces, but the other group is moving closer to al-Qaida and refused. Al-Qaida has brought benefits and problems," Zubeidy says. "They attack the US occupiers. But every day the problems they bring become greater than the benefits.
"Resistance isn't just about killing Americans without any aims or goals," he continues. "Our people have come to hate al-Qaida, which gives the impression to the outside world that the resistance in Iraq are terrorists. Suicide bombing is not the best way to fight because it kills innocent civilians. We are against indiscriminate killing - fighting should be concentrated only on the enemy. They [al-Qaida] believe that all Shia are kuffar [unbelievers] - and most of the Sunnis as well."
Well, there had been attempts before, in 2004, to form a united, non-sectarian political platform for the resistance, but it seemed to hit the skids very quickly. A number of these organisations include both Shi'ites and Sunnis, and operate in the south as well as the north, but that is not sufficient to make them the broad Iraqi political front that is clearly indicated. Most Iraqis support resistance attacks and oppose the occupation, and a Maliki-led government is unlikely to last long if the troops are chased out. But the main anti-occupation force among Shi'ites appears to have been excluded because it decided to participate in the elected bodies under the occupation. And given that one strategy the occupiers are considering is partitioning Iraq into three, a political front that doesn't command cross-sectarian support might well play into America's hands.