A massive demonstration said to be of a million people took Baghdad on April 9 (only found about it now, so good for the "free media") demanding the USA to get out of the state by the end of the year or face armed opposition. The demonstration seem to have been called by the pro-Iranian movement led by Moqtada el-Sadr, which represent about 1/3 of Iraqi Arabs.
It is a smart way to capitalize in the widespread discontent of Iraqis, resentful of the poverty, corruption and sectarian terror that have plagued the country since the unjustifiable US invasion of 2003. It clearly demonstrates that US (plus) policy in regard to Iraq since 1990, when former dictator Saddam Hussein was tricked by Washington into invading the nearby autocracy of Kuwait, a former Iraqi province, has been totally wrong and has favored Iran, consciously or not.
I believe that this favoring of Iran has been conscious because the USA and its main allies in the regions (Israel and Saudi Arabia) strongly favor religious fundamentalism over secular nationalism of any sort (and that's why Hussein was deceived and destroyed and Baathism forbidden). Islamic fundamentalism is a ghetto ideology that can be mostly manipulated into the perfect foe, which you can beat feeling justified and who cannot ever gain friends beyond that specific ghetto. Making fundamentalism, most of which is controlled by the Wahabbis of Saudi Arabia, the main political drive in the region is a way to make sure that neither key US ally is ever threatened because Panarabism (their biggest fear, a secularist, modern, Western-like but not generally pro-Western, ideology) cannot assemble.