The al-Hadba Party emerged from Saturday's vote as a serious challenge to the status quo in Iraq.
Landmark agreement on US troops is delayed as lawmakers seek more checks on Shiite-led government
The pact sets out a three-year timetable for US troop withdrawal. A public referendum on it will be held in July.
The presidential candidate has said he will draw down troops in Iraq if elected.
By the end of July, they hope to finalize a deal that would map out the role and "time horizon" for US troops in the country.
In an interview, a member of the Islamic Army of Iraq speaks of his group's long-term goals.
Growing divisions among pro-US Sunni tribal chiefs threatens to unravel American gains against Al Qaeda.