Ahead of January elections, supporters of the Sadr movement cast ballots for individual candidates – rather than parties – for the first time in a primary poll.
Adel Abdul Mahdi says in an interview with the Monitor that political reluctance to ask US troops for security support should be reconsidered.
Its relative success in Saturday's regional election reflects deep popular dissatisfaction with official corruption.
The region, which has increasingly been at odds with Baghdad, holds elections Saturday for a new regional government.
The attacks underscore the security challenges after the US withdrawal from cities, particularly in the volatile areas in the north.
Amid a huge display of national pride, some expressed concerns that violence could spike again.