By Mohammad Ayatollahi Tabaar, The New York Times: On Friday Iran held its 11th parliamentary elections since the foundation of the Islamic Republic in 1979, and the first since the Trump administration renewed sanctions on Iran and battered its economy.

The voting turnout — 42.5 percent — was the lowest since 1979, and a loose alliance of conservative candidates won. In Tehran, the capital, where about 75 percent of the voters chose not to vote, all 30 seats were won by the conservative candidates loyal to the supreme leader, Ayatollah Khamenei.

The Iranian electorate faces a perpetual dilemma on whether to participate or boycott the elections as the choice of candidates is limited and the Guardian Council — a constitutional committee made up of six clerics and six jurists that vets the electoral candidates — bars those seen as critical of the regime or deviating from its positions.

More than 7,000 candidates, most of them reformists and moderates, including 90 members of the current Iranian Parliament, were disqualified from Friday’s elections by the Guardian Council for having insufficient ideological loyalty, a move that reduced voter participation.

The turnout was higher than Tehran in smaller cities, where citizens have more incentive to vote if the candidates promise better schools and hospitals, improved roads, faster internet, more ethnic inclusion and even individual patronage. As the American sanctions have debilitated the Iranian economy, greater participation in parliamentary elections offers the provinces an opportunity to bargain for a better share of the shrinking pie from Tehran.

In Tehran and other major cities, the parliamentary elections signal not only the citizens’ preferences for particular factions within the regime but also its legitimacy as a whole. Participation rates in the major cities fluctuate more often and reflect the political diversity of the candidates.

In the 2016 parliamentary elections, a high turnout enabled moderate reformist candidates to secure Tehran’s 30 seats in the Parliament. The conservative winners in Tehran, this weekend, were led by Mohammad Bagher Qalibaf, the former head of the Islamic Revolutionary Guard Corps’ air force wing, who is expected to be the speaker of the incoming Parliament. Victories like Mr. Qalibaf’s demonstrate that the Revolutionary Guard is ensuring its presence and domination of the Parliament as well.

Iranians who refused to vote expressed their anger and their disappointment with the Revolutionary Guard’s bloody crackdown on protesters in November, and its cover-up of the accidental shooting of a civilian airplane near Tehran in January. But the trouble with boycotting the elections is that it opens the doors of the Parliament for the most conservative wing of the political system.

Iranian society stands at an uncharted crossroad and the regime is bringing the apparatus of the state under the control of what it considers to be its most loyal elites, one election at a time. In a politically, economically and regionally tumultuous environment, doing so would allow an orderly transition to the next supreme leader.

The brutal response to the November protests across the country showed the will and the capacity of the security apparatus to put down unrest. And a multinational army of proxies under the banner of the Revolutionary Guard’s Quds Force operating from Lebanon and Syria to Iraq and Yemen, have demonstrated Tehran’s will and effectiveness in defending its sphere of influence and fighting threats from hostile states to nonstate participants.

Iran’s constitutional design places the Islamic Republic in a win-win position. High voter participation helps legitimize the regime and a boycott invariably leads to a conservative victory. Elections also serve as a convenient device for the state to learn about and manage popular sentiments before they turn into a mass revolt.

Despite these institutional constraints, Iranian citizens have often outmaneuvered their leaders and stunned the world by using elections as a tool to coordinate nationwide social and political movements.

After the 1989 death of Ayatollah Ruhollah Khomeini, the founder of the Islamic Republic, and with the gradual decline of revolutionary fervor, competition among Mr. Khomeini’s followers provided a narrow political opportunity for Iranian citizens.

By choosing candidates who appeared furthest from the establishment, Iranians revealed their preference for radical change not only to the ruling elites but also to each other. Far from strengthening the regime, elections often turned into national protests, deepening the gap between the state and the society and further polarizing factional politics.

The student uprising in 1999 over the government’s crackdown on the media and the Green Movement against what millions viewed as a rigged re-election of Mahmoud Ahmadinejad in 2009 were direct results of electoral politics and popular frustrations with the regime’s suppression of the people’s struggle for civil rights.

The ruling elites managed this 30-year cycle of elections and protests through a sequence of crackdowns, concessions and more crackdowns. Disillusioned citizens sometimes boycotted elections only to return to the ballot box with vehemence.

Parliamentary elections in Iran have become a consistent predictor of relations between the state and the society. The low turnout in the 2004 parliamentary elections signaled popular disillusionment after the failure of the reform movement that started in the 1997 presidential election to protect civic rights, which led to the 2005 election of Mr. Ahmadinejad to the presidency.

The high turnout in the 2016 parliamentary elections confirmed the high approval rate of President Hassan Rouhani and the nuclear agreement he signed with the United States and other world powers, predicting his landslide re-election the following year.

The conservative victory in the recent parliamentary elections indicates that the Iranian people are disenchanted with electoral politics that deliver nothing. It sets the stage for the ascendance of a hard-line president in the 2021 election if the population’s apathy persists. And the absence of public pressure and elite bargaining will determine the appointment of a possibly even more hawkish supreme leader after Ayatollah Khamenei.

Yet after this electoral cycle, Iranian voters may not easily return to the ballot box. Friday’s election could be the beginning of the death of Iran’s limited electoral politics.

Frustrations against the political system run deep in the country. So do anxieties over external threats to the nation’s security and territorial integrity. It is unclear which direction Iranian society will take.

Elections in the past have laid the ground for cultural exchanges, diplomatic negotiations and a nuclear agreement between Iran and the United States. After the starkly low turnout and the conservative victory, we might be inching toward a more turbulent phase between the two countries.

First publishd in The New York Times. Cartoon by Sofiya Zhelizna.

Mohammad Ayatollahi Tabaar is an associate professor of international affairs at Texas A&M University’s Bush School of Government and Public Service and a fellow at Rice University’s Baker Institute for Public Policy.