TEHRAN, May 22 -- Both are turbaned clerics with well-groomed beards, strong revolutionary credentials and scant affection for the West. Both describe themselves as the natural political heirs of Iran's popular outgoing president, Ali Akbar Hashemi Rafsanjani. Both are 54 years old.
But there are important differences between Ali Akbar Nateq Nouri and Mohammed Khatemi, the undisputed front-runners in Friday's four-way presidential election -- the seventh and most competitive such contest since Islamic revolutionaries toppled the pro-American monarchy in 1979.
Nateq Nouri, the speaker of Iran's parliament, is an arch-conservative who last year described the United States as a "blood-sucking wolf" and recently found it necessary to deny rumors that he would require schoolgirls to wear the tent-like black robe known as the chador.
Khatemi is a scholar and educator who currently heads the national library and who lost his job as minister of culture and Islamic guidance several years ago because he was seen as too permissive.
Although Nateq Nouri was once seen as a shoo-in, given his close ties to Iran's all-powerful religious establishment, the race has tightened in recent weeks, generating excitement among Iranians fed up with the failure of their clerical leaders to root out corruption and deliver on promises of jobs and prosperity.
While a Khatemi victory would be unlikely to temper Iranian hostility toward the West, at least in the short term, it almost certainly would usher in an era of greater political pluralism and social and cultural freedom, in the view of many foreign diplomats and Iranian political analysts.
"If Khatemi wins, things will become more interesting, partly because he is known to be more open-minded and partly because it will be seen as evidence that the system hasn't got everything its own way," said a Western diplomat in Tehran, speaking anonymously.
The race has been a rough-and-tumble one, featuring widespread vandalism of campaign posters and a hearty dose of negative campaigning, especially in the Nateq Nouri camp, which accuses Khatemi of being a "liberal" who secretly wants Iran to have warmer relations with the United States.
But Khatemi has been drawing large and enthusiastic crowds, particularly in Tehran, where he is enormously popular among students and poor people wooed by his liberal economic agenda. On Wednesday evening, an exuberant mob of 5,000 or more turned out to hear him speak at a mosque in east Tehran, waving placards and creating such a ruckus that plate-glass windows shattered under the pressure of so many bodies.
"He's a moderate and he's going to develop the country toward the West," Moshallah Zadeh, a 25-year-old university student, shouted above the din. "He's going to guarantee that we'll have freedom of thought."
Iranian democracy has its limits. Candidates are screened for ideological purity by the Council of Guardians, a conservative clerical body that also has the power to cancel election results without explanation. This year, the council rejected all but four of 238 presidential candidates, including nine women.
Besides Nateq Nouri and Khatemi, the other two candidates are Mohammed Reyshari, a hard-line former intelligence minister, and Reza Zavarei, the deputy head of the judiciary and the only noncleric in the race.
Nateq Nouri enjoys the open support of key government ministers and state-run broadcast media and is widely said to have the backing of Iran's supreme leader, Ayatollah Ali Khameini. If neither candidate wins an outright majority Friday, the contest will be decided in a runoff that many Iranians predict will be rigged in favor of the parliamentary speaker.
That perception was fueled by the council's rejection as un-Islamic of a bill passed by parliament that would have allowed candidates to station observers in polling stations and vote-counting centers.
While diplomats and political analysts do not discount the possibility that Khatemi could pull off a full victory in the first round, whoever is elected will still be subordinate to Khameini and, for that matter, Rafsanjani, who will take over as head of a newly expanded consultative body called the Assembly for Diagnosing the Interests of the Regime.
For those and other reasons, the race has failed to generate much enthusiasm among critics of the regime, such as Dariush Foruhar, a lawyer and former labor minister who now heads the outlawed but tolerated National Party of Iran. "I do not see any difference between them," Foruhar said over nonalcoholic beer the other day. "The whole problem is the religion-oriented status of the government."
But within the narrow context of Iranian politics, the distinction between the two front-runners seems clear.
Although Nateq Nouri has tempered his views somewhat since entering the presidential race, his tenure as parliamentary speaker has been marked by rigid views on social issues and relations with the West. He enjoys strong support in rural provinces, from religious traditionalists and among Iran's powerful bazaaris -- wealthy merchants whose prosperity depends on import and export licenses granted by the government.
Khatemi, by contrast, is considered something of a liberal by Iranian standards. Although he wears the black turban that identifies him as a descendant of the Prophet Muhammad, he has hinted at doubts about strict women's dress codes and a government ban on satellite television. His support is strongest among intellectuals, the urban poor and students -- an especially vital constituency in a country in which the minimum voting age is 15.
Khatemi also has won the endorsement of pragmatists and technocrats, such as Faezeh Hashemi, daughter of the outgoing president, an outspoken advocate of women's rights who now holds a seat in parliament. "If we have only one line ruling over the country, then the country will face stagnation," Hashemi told foreign journalists today. "There is a direct line between freedom and moderation."
Among ordinary Iranians, Khatemi has tapped into widespread anger over government mismanagement of the economy -- unemployment is estimated at nearly 30 percent -- and meddling in the private lives of individuals.
A poll published in the newspaper Akhbar this week showed Khatemi favored by 59 percent of the electorate and Nateq Nouri by 30 percent, although other polls have shown the reverse.
Incumbent: President Ali Akbar Hashemi Rafsanjani, who must step down in August after eight years in office.
Electoral system: Political parties are banned, but groups or factions form to support individual politicians. To win the presidential election, a candidate must gain an absolute majority of more than half of all votes. If no clear winner emerges, there will be a runoff between the top two, probably a week later.
Electorate: Universal suffrage for 33 million people, age 15 and over who can vote at 33,400 polling stations.
Former minister of culture and Islamic guidance, known for advocating less heavy-handed social and cultural policies and regulations; backed by a coalition of centrists close to Rafsanjani. He has gained wide support among women, young people and intellectuals.
Ali Akbar Nateq Nouri, 54
Speaker of parliament and leader of a conservative group of Shiite Muslim clergymen. He is close to the traditional merchant class that feels threatened by foreign investment.
Mohammed Reyshari, 51
Was a revolutionary court judge and became revolutionary Iran's first internal security minister; a fierce defender of Islamic values, known for his hard-line conservative views.
Reza Zavarei, 59
A lawyer who is deputy head of the judiciary. He is the only one of the four candidates who is not a cleric.
Population: 67 million (expected population in 2010: 88 million)
Capital: Tehran with 6.8 million people
Major ethnic groups: Persian 51%; Azerbaijani 24%; Kurds 7%
Religion: Shiite Muslim, with some Sunni Muslims
Life expectancy at birth: males 66 years; females 69
Gross domestic product per capita: $5,380 (1993), adjusted for purchasing power
Industries: Oil (90 billion barrels of proven oil reserves, about 10% of world total), petrochemicals, cement
Exports: $16 billion (1993); major partners were Japan, France
Imports: $23.7 billion (1993); major partners were Germany, Japan and Italy
Unemployment: 10.7%; high under-employment rate
SOURCES: Reuter, World Almanac, U.N. Human Development Report, World Bank
@CAPTION: Iran's presidential election today, its most competitive since the 1979 revolution, could usher in an era of greater political pluralism.
@CAPTION: Women in Tehran pass by campaign posters boosting Ali Akbar Nateq Nouri, a leading candidate in Iran's presidential election today.