Difficulties in obtaining a sample.
It would be interesting to see the details of how the random sample was obtained. Were the names of those polled pulled from the -
Phonebook?
Voter registration?
Physical Address?
Where were the interviews held? (How practicle would "Doorknocking" in Bahgdad be?)
What was the percentage of refusals to cooperate?
In an unstable occupied country, was there an incentive to lie to the pollsters?