Iranian President Hassan Rouhani staked his political future on opening Iran ever so slightly to the outside world and overcoming hard-liners' opposition to secure a historic nuclear deal in exchange for relief from crippling sanctions.
He'll soon find out if voters think it's enough to keep him in the job.
The 68-year-old cleric, a moderate within Iran's political system, has history on his side as Iranians vote for president on Friday.
No incumbent president has failed to win re-election since 1981, when Ayatollah Ali Khamenei, the current supreme leader and most powerful man in Iran, became president himself.
Political analysts and the scant polling data that's available suggest Rouhani will come out on top among the four candidates left running, though an outright win is by no means assured. Failure to secure a majority tomorrow would send the two top vote-getters into a runoff a week later.
His supporters streamed into downtown Tehran streets thick with police for rallies that lasted into the early hours today, just ahead of a 24-hour no-campaigning period before the vote.
Wearing Rouhani's signature purple on ribbons and loosely draped headscarves, they honked, cheered and chanted slogans in support of Mir Hossein Mousavi, one of two Iranian opposition leaders under house arrest since 2011 who back Rouhani.
The rallies were largely peaceful even as Rouhani supporters faced off against smaller crowds supporting his main rival, hard-liner Ebrahim Raisi, though police rushed reinforcements to break up Rouhani rallies that grew large enough to block traffic.
Working against Rouhani is a sense among many Iranians that the 2015 nuclear deal, which saw Iran accept limits on its atomic energy program, has failed to deliver an economic windfall.
“No matter who's the next president, whoever comes to power should bring a better economy,” hair stylist Reza Ghavidel said.
Although nuclear-related sanctions were lifted because of the deal, other US and other international sanctions remain in effect. That leaves banks and many big corporations wary of doing business with Iran.
Unemployment, meanwhile, remains stuck in the double digits, with nearly a third of Iranian youth out of work, according to the International Monetary Fund.
“This election is about the economy. I don't think most voters are thinking about the soul of the nation right now,” said Cliff Kupchan, the chairman of the Eurasia Group. “The numbers are looking better … but the voters aren't feeling it.”
Rouhani's stiffest challenge comes from Raisi, a law professor and former prosecutor who heads an influential religious charitable foundation with vast business holdings. He is seen by many as close to Khamenei, and has even been talked about as a possible successor to him. Khamenei has stopped short of endorsing anyone.
Raisi won the support of two major clerical bodies and promised to boost welfare payments to the poor.
His populist posture, anti-corruption rhetoric and get- tough reputation bolstered by his alleged role condemning inmates to death during Iran's 1988 mass execution of thousands of political prisoners are likely to energize conservative rural and working-class voters.
In a bid to woo younger voters, he has even turned to appearing in a viral video next to a tattooed, once- underground rapper named Amir Tataloo despite his own history of supporting the cancellation of concerts on moral grounds.
Mostafa Hashemitaba, a pro-reform figure who previously ran for president in 2001, and Mostafa Mirsalim, a former culture minister, also remain in the race.
The ruling system put in place after the 1979 Islamic Revolution combines conservative clerical oversight and state control over large parts of the economy with tightly regulated but still hotly contested elections for key government posts.
All candidates for elected office must be vetted, a process that excludes anyone calling for radical change, along with most reformists. No woman has been approved to run for president.
Under Iran's system, the president is subordinate only to the supreme leader, who is chosen by a clerical panel and has the ultimate say over all matters of state.
The presidency is still a powerful post, with considerable influence over domestic policy, the state bureaucracy and foreign affairs.
A victory for Rouhani could lead to a further loosening of limits on personal freedom, while a hard-line win could set Iran up for a renewed bout of confrontation with the West at a time when US President Donald Trump has called for a tougher line on Iran.