Muqtada al-Sadr played a prominent part in the memoirs of the US civil administrator of Iraq between 2003-2004, Paul Bremer, with the latter describing the former as difficult to decipher and not easy to deal with, when compared to other opponents of the United States in Iraq. And now, more than one decade later, Sadr remains the preeminent troublemaking political leader, whose unexpected decisions surprise his challengers and rivals alike.

Sadr enjoys widespread popularity among Shiites and hails from a religious family with great influence among the populace — a family that lost two great religious leaders killed by Saddam Hussein's regime, namely Muhammad Baqir al-Sadr (1935-1980) and Mohammad Sadiq al-Sadr (1943-1999). His lineage thus afforded him great social legitimacy, allowing him to wield extensive power that changed existing political equations in unexpected fashion, as he imposed his will on the overall political process.

Thanks to this legitimacy — and as a result of his political and social influence — Sadr skirted a 2003 arrest warrant issued in his regard by a judge in the Najaf court on charges of being involved in the assassination of prominent Shiite leader Sayyid Abdul-Majid al-Khoei on April 10, 2003. He also managed to avoid arrest by US occupation forces following his involvement in the killing of a number of troops belonging to these forces, following attacks by the armed resistance movement, Jaish al-Mahdi. US forces were unable to capture him, given his popularity in the Shiite street. He then moved to Iran and stayed there until 2011.

In addition, the Sadrist movement cast the winning vote in Nouri al-Maliki assuming the country’s premiership for two terms in 2006-2014, as Sadr supported Maliki against the candidates of other blocs of the Iraqi National Coalition, which was then tasked with nominating a prime minister. Later, Sadr played a leading role in preventing Maliki’s ascension to power for a third term in 2014.