Mayor of Tehran Mohammad Baqer Qalibaf, a figure in the principlist political faction who struggled to drum up support for his presidential campaign by hammering Rouhani, made a decision to quit the race on Monday in favor of Raeisi. That is not to say, however, that all of Qalibaf's supporters will automatically vote for Raisi.
As many as 16.2 percent of the respondents said they had not yet decided whether to vote or not. "We can not take the renewal of his mandate for granted".
Many now believe that the vice president may contest the presidency for real at the next election in 2021.
The election is largely viewed as a referendum on the 2015 nuclear deal struck with world powers shepherded by Rouhani's administration.
At the meeting, both Raisi and Qalibaf announced their readiness to withdraw in favour of the other. The two men draw on different constituencies, according to Aniseh Bassiri Tabrizi, research fellow at the Royal United Services Institute in London.
If no candidate win more than 50 percent of the votes in the election on May 19, a run-off will be held a week later.
He said those forces were telling voters they should fear the scenario of Rouhani's reelection, because the outgoing president plans to cut off all financial aids meant to citizens. Raisi and Ghalibaf represent the hard-line or conservative faction of Iranian politics. "He should be able to drive a substantial proportion of these voters to the ballot box". "The fact is that Raisi is not a very well-known person in Iran, so I think that Rouhani will win", she said.
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"We will use Qalibaf's experiences and his managerial capabilities in the next government", Tasnim news agency quoted Raisi as saying on Monday.
Under Iran's system, the powers of the elected president are circumscribed by those of the conservative supreme leader, Ayatollah Ali Khamenei, who has been in power since 1989.
A bruised Rouhani may struggle to secure enough votes to avoid a second ballot, prompting some analysts to predict he might lose in a run-off against Ebrahim Raisi, a former prosecutor Khamenei has helped build up, appointing him previous year to oversee Iran's largest shrine and its charitable foundation. He was deputy head of the judiciary for 10 years before being appointed in 2014 as Iran's prosecutor-general.
Raisi and Qalibaf were following the same campaign tactics, criticizing Rouhani's economic record and his policy of detente with the West. But he has little direct political experience. "Rouhani's camp has lost an easy target to beat up on".
High voter turnout has generally favored moderate and reformist candidates in Iran.
Seeking a second term, pragmatist President Hassan Rouhani, 68, remains the narrow favorite, but hardline rivals have hammered him over his failure to boost an economy weakened by decades of sanctions. Mostafa Mirsalim is a conservative and former culture minister.