Now more than ever, Islamic clerics form the backbone of revolutionary Iran. They are at every level of society. The most important political event of the week, for instance, is the public prayer on Friday, the equivalent in Islam of Christian Sunday. Every city has its own Friday prayer leader, except the capital, Tehran, where different religious personages share the function.
Two weeks ago President Ali Khamenei, a clergyman, took his turn. On the campus of Tehran University thousands of the faithful sat in rows. The men sat apart from the women, who are allowed to hear the prayer leader but not see him.
Mr. Khamenei, who survived an assassination attempt in 1981, faced the crowd from a stage, a gun in his left hand. He spoke about Iraqi air attacks on densely populated neighborhoods. His speech was interrupted regularly by shouting from the crowd: ''Death to America, death to the USSR, death to Israel, death to France.''
After his sermon in Farsi, Mr. Khamenei read a message in Arabic to be broadcast by Tehran's shortwave radio service. He then went down a few steps to a hole - to make himself less vulnerable to assassination attempts, security agents said. From the hole he led the prayer.
According to the Constitution, the President enjoys limited powers. Although he appoints the prime minister, his choice must be approved by the Majlis (parliament). Real power is held by the Majlis and the Cabinet.
The man on the rise in Tehran is Prime Minister Hossein Mussavi. Last July he launched a vocal attack against bazaar shopkeepers whom he blamed for shortages and raging inflation. Very skillfully, Mr. Mussavi said most ''bazaaris'' were honest but that their ranks had been infiltrated by economic terrorists speaking in their behalf.
First Ayatollah Ruhollah Khomeini, then several high-ranking clergymen backed Mussavi's move. This brought him a great deal of popular support, and in the press he quickly outshone Hashemi Rafsanjani, speaker of the Majlis.
The government set up special courts to deal with economic crimes. A few weeks later, Mussavi succeeded in getting rid of five members of his Cabinet. Among them was Minister of Commerce Habibollah Asgar-Oladi, who was said to be the political representative of a group of wealthy tradesmen opposed to any reform in the Iranian society.
Observers in Tehran saw this as the beginning of an all-out confrontation between reformist and conservative Muslims. But Ayatollah Khomeini stepped in with a plea for unity.
''He understood that with the war raging at the border,'' an Iranian said, ''the revolution couldn't afford a new internal conflict.''
Ayatollah Khomeini's opponents say that middle-class businessmen are the pillars of his regime. ''Attacking them would be suicidal for the Islamic Republic,'' they add.
Iran's leaders are bracing for general parliamentary elections scheduled for next spring. It is not yet known how may groups will participate. The government will exclude candidates who do not support the idea of having a religious guide for the country.
Former Prime Minister Mehdi Bazargan, who leads parliament's only opposition group, the Liberation Movement of Iran, said recently: ''The survival of the Islamic regime is linked to the organization of totally free elections.''
His words drew sharp criticism in the press.
Supporters of the Hizbollahi (Party of God) accuse Mr. Bazargan of being pro-American. Should Mr. Bazargan and his friends decide or be forced to renounce their candidacies, Islamic fundamentalists would be poised to gain full control over the Majlis.
The elections will probably be followed by the formation of a new Cabinet. The reorganization of the judicial system will likely be one of its top priorities. At present there are two judicial systems - one revolutionary, the other civil.
The current Cabinet would like to put revolutionary judges under the control of the civil judicial system. Revolutionary magistrates are reputed to be very hard on political opponents. They still control Evin Prison, Tehran's main jail, refuse any government interference in their job, and oppose any contact with international human rights associations.
By the government's plan, the chief judge in the civil judicial system, Ayatollah Mussavi Ardebili would run the entire judiciary. He is said to be considering inviting human rights investigation groups to Iran.
The outlawed communist Tudeh Party was the last organized force that could have challenged the power of Ayatollah Khomeini's followers. The People's Mujahideen, who once led the armed struggle against the regime, appears to be knocked down.
Exiled monarchists have formed a united front around Cyrus Reza Pahlavi, the late Shah's son. Although this coalition is gaining some support within Tehran's upper middle class, the great majority of Iranians believe the days of the Pahlavi dynasty are well over.
The question of the Ayatollah Khomeini's succession remains, however. The religious assembly that will choose the new religious guide has never said it openly, but Ayatollah Hossein Montazeri appears to be the front runner. In Tehran's newly built airport terminal, passengers are welcomed by two huge pictures of Ayatollahs Khomeini and Montazeri standing side by side.