“What they are trying to do is demonstrate that they can deliver services in the south,” said Marisa Cochrane Sullivan, a fellow at the Washington-based Institute for the Study of War who has written about the Sadrist movement. “This is part of their transformation. They can no longer make the case that they have to be there to protect the Shiites from Al Qaeda or other Sunni groups.”

She added, “The Sadrist strategy is to find areas where they can win the art of political argument.”

MR. SADR emerged from the national elections in 2010 as a kingmaker whose support allowed Prime Minister Nuri Kamal al-Maliki to secure a second term. With the majority of results in from the recent local elections, it appears Mr. Sadr’s support has diminished in much of the south — where leaders have not had the same success as Mr. Dwai — with the exception of Maysan Province.

The results underscored two things: that Mr. Sadr has more work to do in expanding his constituency through governing in much of the south, and that Mr. Dwai is the movement’s brightest star.

Amara, the capital of Maysan Province, lies in Iraq’s Shiite heartland not far from the Iranian border. The area was once a bloody arena for Hussein’s 1991 crackdown on his rebellious Shiite population and later, under the American occupation, a battleground for militias backed by Iran.

When American troops were preparing to leave Iraq at the end of 2011, the area was still considered so dangerous that American commanders paid local sheiks to clear the roadways of homemade bombs and Iraqi security forces carried out a wide-ranging military operation to drive out the armed groups.

Far from the tumultuous center of Iraq — where Sunni militias are now fighting the Shiite-controlled government, and where car bombs and suicide attackers strike with impunity — Amara has few terrorist attacks, and violent murders number in the single digits annually, said Mr. Dwai, who is also the head of the security committee in the local council.