The Guardian Council of the Islamic Republic of Iran oversees the process of application and approval of presidential candidates. According to article 115 of the Iranian constitution, the candidate has to have “religious and political personalities” and he has to fulfill the following requirement:
Be of Iranian origin and in possession of the Iranian nationality. The candidate shall be of administrative capacity and resourcefulness, and above 21 years old. Furthermore does the constitution require the candidate to have a good past record and be trustworthy and have piety. The main qualifying factor for running as a presidential candidate is a convinced belief in the fundamental principles of the Islamic Republic of Iran and in the religion of Islam.
After vetting all presidential hopefuls, the Guardian Council publishes an official candidate list.
It was expected that the current Iranian Minister of Health and Medical Education, Marzieh Vahid Dastjerdi, would run for president. She is the first elected female minister of Iran and known as a hardliner for her conservative stands. She declined a candidacy even though the Guardian Council did announce in January 2017 that they will not disqualify a candidate on the basis of their gender. In comparison to Vahid Dastjerdi, the current Iranian president, Rouhani, is known for being more pragmatic, which is one of the reasons the nuclear deal with the United States was able to come together.
The Guardian council rejected the candidacy of the former president, Mahmoud Ahmedinejad, as it was feared that this candidate could divide the country.
In the recent decades Iran experienced a steady increase in population, which is reflected by its electoral roll.
The voter turnout for the presidential elections has been historically stable and high. According to the law, the President of the Islamic Republic of Iran is elected through an absolute majority. This means, that the winner needs to receive at least 50.1 percent of the votes. If none of the candidates receives more than half of the votes, the two candidates who scored the most votes will go into a run-off voting. The two-round election system was used in the 2005 Iranian presidential election when Akbar Hashimi-Rafsanjani received 21 percent of the votes and Mahmoud Ahmedinejad received 19.4 percent. Three days after the official vote, they entered a second election, which was won by Ahmedinejad.