FOUR YEARS ago it still seemed possible to many Iranians that their country's political system could be an instrument for genuine democratic change. With the support of a broad coalition, reformist President Mohammad Khatami won reelection in a landslide. As tomorrow's election of Mr. Khatami's successor approaches, those hopes are gone: The past several years have brought not the enactment of his liberalizing agenda but the consolidation of power by the Islamic clergy and its supreme religious leader, Ayatollah Ali Khamenei. The elected president has proved to be a feckless figure; his onetime supporters are divided between those who back a new liberal candidate and advocates of a boycott. Whether they bother to vote, most Iranians no longer believe that their elected government has any meaningful authority.

They are right, of course -- yet the results of the election will matter. The presidential election campaign has revealed intriguing splits in the Iranian political establishment, not just between democratic reformers and authoritarian conservatives but among the hard-liners themselves. The apparent front-runner, 70-year-old former president Ali Akbar Hashemi Rafsanjani, though no democrat, is clearly a rival to Mr. Khamenei. If elected, he probably will try, like Mr. Khatami before him, to weaken Mr. Khamenei's power over the government, judiciary and press; given his stature and political skills, he might have more success. His chief conservative opponent, Mohammad Qalibaf, a 43-year-old former police chief, represents a new generation of fundamentalists who embrace clerical rule.

Though they do not challenge authoritarian rule, Iranian elections do force candidates to cater to the real opinion of the public. Intriguingly, not just reformist candidate Mostafa Moin and Mr. Rafsanjani but also some of the most conservative contenders have calculated that the best way to win votes is to offer the hope of domestic reforms and improved relations with the United States. On state television this month, one candidate declared that "if America had a strong president who could put forward a proposal to Iran that was worthy of the Iranian nation, then many things would change." This came from Mohsen Rezai, a former Revolutionary Guards commander and secretary of the clerical council that blocked most of Mr. Khatami's reforms.

Four years ago U.S. policymakers debated whether to engage Iran's elected reformists or hope for a democratic revolution led by students and other militants. Now there is no real choice: Both groups have been seriously weakened, and the pro-democracy movement is in disarray. The sentiments of the Iranian public, however, haven't changed. As the campaign has shown, a powerful yearning for political freedom and other human rights remains. This election won't bring about that revolution, but it has made the cracks in the aging Islamic dictatorship a little wider -- and demonstrated once again that only a minority of Iranians still accepts its ideology.