BAGHDAD—Hadi al-Mahdi, a man you might call the Rush Limbaugh of Iraq, bounded up the stairs to a radio studio in a converted villa beside the Tigris River. “;Today,”; he said, with impish determination, “;we are going to defend the Sunnis.”;

For the next hour, al-Mahdi, a Shiite married to a Kurd, did just that. In a sonorous, sarcastic voice he ridiculed the murky process that disqualified Sunni candidates in Iraq's recent elections as an assault on the multiethnic, multifaith democracy Iraq is supposed to be creating.

As the sun set on another dusty Baghdad evening rush, he condemned not only the man behind the disqualifications (”;He's illiterate.”;), but also Prime Minister Nouri al-Maliki (”;Is there glue in your chair?”;); al-Maliki's main challenger in the election, Ayad Allawi; the ministers of education and electricity; “;this dirty Parliament”;; and the rest of Iraqi officialdom “;living in the Green Zone, while your family is living abroad.”;

He added: “;Who is going to die? Your son?”;

Al-Mahdi's program—“;To Whoever Listens”; on Radio Demozy, 104.1 FM—is a thrice-weekly, populist jeremiad of all that is wrong with Iraq's fledgling democracy, and one measure of what the overthrow of Saddam Hussein has led to.

His is not the only radio talk show in Iraq, but it is arguably the most breathtaking exercise of free speech in a place where its limits are still being established. It is, by some accounts, one of the most popular programs on the air in Baghdad. It is, without question, immensely entertaining.

“;They tell me not to talk about politics,”; he said, theatrically, during another evening broadcast after the station director quietly entered the studio during a music break (and said no such thing about avoiding politics).

“;They passed me a note,”; he went on. “;What am I supposed to talk about? My mother?”; (She is a favorite foil.)

He then excoriated the sorry state of higher education, the corruption and bribery that had crept into universities, the sectarian influences and the proliferation of dubious doctorates among politicians, including one, he sardonically noted, that had been granted for the study of Hussein's speeches.

“;They call them doctors,”; he said, “;but what can they teach now?”;

Al-Mahdi, 44, is a garrulous man, a playwright, filmmaker and columnist with a provocative streak that sent him first to jail and then into exile during Hussein's rule.

At a time when the Baath Party controlled everything, he had the audacity to stage a play at a public festival without having it vetted first. Actually, he submitted a different script altogether.

He called his play “;Farewell, Old Strange World.”; It was an Iraqi retelling of Machiavelli's “;The Prince.”;

“;When I remember it now, I was crazy,”; he said, smoking in the kitchen of the villa before another program. “;What the hell was I thinking?”;

He and seven others were arrested and spent six months in jail until the theater union appealed for their release on the grounds they were young, foolish and harmless. He still has back pain, he says, from interrogations.

He finished his studies at the Academy of Fine Arts in Baghdad in 1989 and fled to Syria (where he briefly lived in the same building as al-Maliki) and ultimately Sweden, where he worked in Arabic-language radio and TV.

He is strikingly free of bitterness for a man who, like so many Iraqis, suffered under Hussein. When he was a teenager during the war with Iran in the 1980s, he said, he was ordered to attend an execution of traitors in a soccer stadium. Among the men marched in and shot was his 30-year-old brother.

“;This could have made a criminal of me,”; he said. “;Instead, I decided to become a democrat.”;

He returned to Iraq three years ago after 18 years in exile. He began his own doctoral studies in the globalization of theater and resumed writing plays with the same acerbic edge applied to Iraq's new leaders. His next project turns “;Hamlet”; into a meditation on the American and Iranian struggle for power in Iraq.

He began the radio program two years ago, giving him a platform for antigovernment tirades that would have been unthinkable before 2003, and still are in much of the Middle East.

Radio Demozy is a small, independent station, a novelty in a country where most media is owned by the state or political parties, with political agendas to fit them. Its staff is young, idealistic and as decidedly secular and liberal in its outlook as al-Mahdi is. It loses money.

“;There are two matters that do not comply with logic: marriage and politics,”; said its owner, Ibrahim al-Saadi, who also runs a TV station and a newspaper. “;Ask me why we get married. Then ask me, why do we tread in politics? I have no answer. Both are full of headaches and lack profit.”;

Iraq has no ratings systems, but a recent study commissioned by the market research company, IREX, found that Radio Demozy reached 4 percent of all Iraqis, though its broadcasts reached only the country's center.

A taxi driver, Jassim Muhammad Hussein, shushed a customer when his show was on.

“;Listen, listen to him,”; he said, sounding stunned by the bluntness of al-Mahdi's critiques. “;I salute him for his guts.”;

The station measures the popularity of al-Mahdi's show by the number of callers. There were few in the beginning. Now al-Mahdi cannot answer them all. The callers thank him. They question him. They complain, most still reluctant to say their names.

One said he had been asked to pay $200 for the right to take an exam for the civil service at a university. This led to a tirade about the pernicious influence of corruption in higher education.

“;The university is full of professors who are not qualified to be the guards,”; al-Mahdi said, his voice as soothing as ever.

He described the show as “;the people's pharmacy,”; the ability to air grievances being the medicine of a democratic society.

“;Iraq has been through 35 years of silence,”; he said. “;Iraqis are not used to their voices being heard.”;

His relentless attacks have drawn the attention of the authorities, who have complained to al-Saadi or the station director, Salem Mousa al-Sudani, who winced more than once at al-Mahdi's remarks. The station has received more ominous e-mail messages, and once a flier on the villa's doorstep, which is in the central Karada district of Baghdad. “;We will kill you and cut off your head,”; it read.

“;Frankly speaking, it's an adventure,”; al-Mahdi said later. “;I live alone, and I am scared, but when I'm behind the microphone, I am superman.”;

Yasmine Mousa contributed reporting.