Here’s an interesting perspective on why the Sunnis (and other Iraqis – it’s not just the Sunnis) oppose the federalism parts of the draft constitution.
For one, the Iraqi government isn’t allowed to deploy the army to the region without express permission from the regional parliament. The ability to develop more efficient administration of resources and development isn’t the problem, it’s the local militias affiliated with political parties in parliament that want to keep power by suppressing freedom and intimidating people. This happens to a large degree in the south, in places like Basra, where the religious Shiite and Iran-affiliated Badr militia has been known to harass people for doing things “unIslamic.” It is a bad precedent to set, and one that can lead to an all out struggle for the country’s unity should the south ironically decide to secede due to its personal consolidation of power.
The other problem is the distribution of resources, which is another reason why many people of different ethnic and sectarian backgrounds oppose the current federalism. It isn’t about being Sunni or Shiite, it’s about being stuck in the middle of the country with few resources for development. Currently, the federal government takes a percentage of all exploited resources, but all undeveloped resources will remain the sole propriety of the regions. This is coupled with the previous concerns that the federal government won’t be able to stop the resource-rich north and south from seceding, leaving them high and dry.
Basically, with this wording in the US constitution, the South would have been able to secede and the US government under Lincoln would have been constrained by the constitution so that militarily attempting to hold the country together would have been impossible.
So it’s not unreasonable to see things from the Sunni point of view here.
Although, resource distribution in the US is closer to the above reading of the Iraqi situation. For instance Alaska has no sales tax and virtually no income tax because of their oil revenue.