Iranians will vote today in the country's first presidential election since incumbent leader Hassan Rouhani signed a deal with world powers to rein in Tehran's controversial nuclear program nearly two years ago.
- Iranian President Hassan Rouhani is up against Islamist Ebrahim Raisi
- The economy, religion, and the Iranian nuclear deal will all be determining factors
- Rouhani has a liberal economic agenda, Raisi styles himself as a man of the people
The economy will play an enormous role in the outcome of today's vote, which could also determine who replaces the current, ageing supreme leader Ayatollah Ali Khamenei.
Key sanctions have been lifted and tens of billions of dollars in assets unlocked but many ordinary Iranians have been disappointed with the results.
President Hassan Rouhani faces a stiff challenge from hardliners, who are hoping to capitalise on those economic disappointments.
Mr Rouhani is promising "progress and hope" and his supporters have come out in droves, at one point even filling a stadium with a huge crowd doing the Mexican wave.
But Mr Rouhani is widely seen as having overpromised when he sold the nuclear deal, and many have been disappointed with the economic benefits that flowed from lifting anti-nuclear sanctions.
Inflation is down dramatically and growth is up, but so is unemployment — youth unemployment is above 25 per cent.
Mr Rouhani promotes a liberal economic agenda, of free markets and foreign investment, and he has raised energy prices without matching handouts to the poor.
In contrast, his hard-line opponent Ebrahim Raisi — who is promising to boost handouts and subsidies — has styled himself as a voice of the poor and disenfranchised.
"The main rival of [Rouhani's] Government is its four years of poor performance," Mr Raisi says.
Mr Raisi is a protege of Iran's supreme leader Ayatollah Ali Khamenei.
In the 1980s he helped sentence thousands of political prisoners to death. He also has the backing of the Islamic Revolutionary Guard Corps, the country's most powerful security force, with vast economic interests.
Mr Rouhani is no dissident — he is a pragmatic member of the ruling elite.
He has also sought substantial support from the reformers who staged mass protests and suffered brutal repression at the hands of the Revolutionary Guard after controversial elections in 2009.
And in the final week of campaigning he took the gloves off, zeroing in on sensitive issues such as warning the Revolutionary Guard not to interfere in the election and speaking out against their extensive business deals.
In a live TV debate, he told Mr Raisi not to abuse religion for power, and he put the spotlight on his opponent's powerful backers.
"Some security and revolutionary groups are bussing people to your campaign rallies ... who finances them?" he asked.
He has also hinted at a wider agenda which would advance human rights and curtail the IRGCs military activity, promising to lift the many remaining sanctions on Iran and asking for a convincing mandate to legitimise a push for greater change.
But that is something he has failed to do thus far. And while ultimate power in Iran rests with the supreme leader, these elections do matter.
That is why Ayatollah Khamanei — in a thinly veiled rebuke to Mr Rouhani — has declared some of the remarks made during the campaign "unworthy of the Iranian nation".
That, and general disaffection, could cost Mr Rouhani vital votes.
The Ayatollah — who wields the real power in Iran — is 78 years old, and whoever is prime minister for the next four years could sway the selection of, or become, his successor.