It is by no means yet certain that Moqtada Al-Sadr can convert his strong showing in Saturday’s Iraqi general election into actual governmental power. Once the final results are declared, probably on Monday, Baghdad politicians will go into their normal protracted huddle to build a coalition government. In all elections since the fall of Saddam Hussein, no one party has ever been sufficiently strong to govern alone.

Nevertheless, the defeat of Prime Minister Haider Al-Abadi, who is apparently trailing in third place, is of great significance, not simply to the Iraqis themselves but to a region that is being menaced by ever-greater Iranian interference. Sadr was once seen by the Americans as a menace, who challenged their occupation, and for a while he enjoyed the backing of Tehran, eager to do anything to frustrate Washington and its bumbling attempts to rebuild the country it had destroyed.

But Sadr proved too unruly to be a useful ally for Iran. Whatever else may be said about the involvement of his Mahdi Army in the bloodletting aimed at the minority Sunni community, he has emerged as a nationalist. He has not allowed his Shia background to permit the ayatollahs in Tehran to use him as a cypher, a tool for their own malign campaign of disruption in the country. His refusal to toe the Iranian line caused supreme leader Ali Khamenei to mutter angrily earlier this year that he would not allow “liberals and communists to govern Iraq”.

This comment would seem to reveal that Khamenei regarded Abadi’s government as illiberal and, therefore, entirely acceptable.

From his clerical family’s heartland in Baghdad’s rundown Sadr City where he is the unquestioned leader of three million poor and disadvantaged Iraqis, Moqtada Sadr has expanded his influence across the country. The crux of his electoral message has been a campaign against the massive corruption that has seen Abadi and his cronies become rich while essential services, healthcare, education, roads and other infrastructure remain in a parlous state. The country’s oil income has been syphoned off for the benefit of the elite, in much the same way that Iran’s economy has been plundered by the ayatollahs and their praetorian Revolutionary Guard.

The party that is currently in second position in the polls is led by Hadi Al-Amiri, head of the Badr militia. Its fighters have done most of the heavy lifting in the successful campaign that has largely driven Daesh (the self-proclaimed IS) from Iraqi soil. The army, for all its brand-new US equipment, played a smaller role in this victory, not least because its command structures were hollowed out by Abadi’s deeply incompetent predecessor Nouri Al-Maliki. The best weaponry in the world cannot make up for general lack of leadership.

The now deeply divided Kurds played an important role in the defeat of Daesh in the north of the country. If they decide to back Sadr and his Iraqi Communist party allies, the once-maverick cleric may have a reasonable chance of taking power. Sadr wants an end to sectarian quotas for government jobs, the disbandment and incorporation of all militias into the Iraqi army and genuine reconciliation between all Iraqi communities.

For want of anything better, Washington has backed Abadi’s failed government despite its closeness to Iran. Moqtada Sadr now offers a probably far better option.