In campaign speeches, Raisi accuses Rouhani of ignoring the poor and failing to deliver on the promised benefits of the nuclear agreement. Meanwhile, Rouhani says he needs more time to rebuild the economy, which was shattered by years of sanctions and mismanagement when he took over in 2013. "We're not opposed, but do not crowd out other people". And in a tight contest, given the conservatives' renowned ability to get out their vote, that might be enough to give Raisi victory.
"Having an Iranian president publicly endorse provocative military maneuvers could fast track a confrontation that claims the nuclear deal as its casualty", they said. He's done that - in the process restoring oil output, spurring growth and slashing inflation.
"The main rival of [Rouhani's] Government is its four years of poor performance", Mr Raisi says.Rouhani enjoys Khamenei's blessing, otherwise he would not have been permitted to run. Mr. Rouhani would be a valuable voice during this time, one who could help Iran truly embrace future opportunities of global engagement and retreat from the dogmatic rhetoric of the ayatollahs.
Hardliners dominating the judiciary and security services have stood in the way, his defenders say.
Another poll by the International Perspectives on Public Opinion also reflected a distinct advantage for Rouhani, but did show he was vulnerable.
Every four years for almost the last four decades, Iran's elections fool many into believing they are democratic and dynamic. Zeinab Asgharpour and fellow Rouhani supporters roam Tehran's streets, pleading for voters to keep that streak alive. "Not anymore", he said.
Rouhani has come out swinging against hard-liners, including the powerful Revolutionary Guard, which plays an outsized but unelected role in Iranian politics. "Rouhani has failed to bring changes".
He has pushed the boundaries over the past fortnight, criticising the continued arrest of reformist leaders and activists, and calling on security agencies not to interfere in the vote.
"I am disappointed with Rouhani". These people have been hailed by the leader of the opposition as a beacon of light for the people of Iran who so desperately want the freedom and democracy that they deserve. Women comprise more than half the population and have lesser rights than men in areas including inheritance, divorce and child custody. Rouhani's problem is that nothing much has changed in the economy either.
"But he is way ahead of Raisi".
The Rouhani government granted more than USD4 billion worth of loans to recession-hit small- and medium-sized enterprises past year to help them get back on track.
"I predict a record participation rate". In that regard, Bayram Sinkaya, a prominent academic and expert on Iran, commented on the matter to Daily Sabah and said that neither Hashemitaba nor Mirsalam has a good chance of winning the elections, noting that all of the traditional conservatives, technocrats as well as reformists and supporters of former President Akbar Hashemi Rafsanjani have gathered around Rouhani.
In addition, as nearly all the political oppositions had been wiped out since the Iranian Revolution of 1979, even if they have differences in their programs, the presidential candidates are all different branches of the same tree. "You want to manage the country?" The principlists aren't in favor of economic liberalisation or in opening up to the outside world, leaving the biggest issue between the two sides the nuclear deal with America.
The largest number of polling stations - 55 - would be in America, where more than 1 million Iranians live, he said.
A third candidate, Hashemi Taba, said in a statement that he would vote for rouhani on May 19 but he has not announced his withdrawal officially to the Interior Ministry yet.