the Iraqi attack was pre-planned with Iran (according to CIA )and have little to nothing to do with the referendum, it is the united state's attitude which encouraged the attacks. now Kurds are weaker and who is stronger ? of course Iran and its puppy government in Iraq. 
if the US think's that abbadi is better, well that reminds me how they thought that Ruhani is better than Nijadi !! The US is trying to sell Kurds out and buy Iraq government with weapons, but Iran has already bought them with ideology along with weapons and money, so the US is like someone trying to extinguish the fire with oil !! Kurds were the only group in the middle east who like America .. now nobody does ..it's not a coincidence that everything US government did since the 80s has only made Iran stronger, it is the '' sell your friends'' mentality responsible of that along with the US ignorance of the regional history and mentality.