The two candidates have fundamentally different visions of Iran's place in the world, and while the Supreme Leader has the final say on all matters of the state, Iranian presidents can still set the tone.

AD

As the incumbent, Rouhani has an advantage: Every Iranian president since 1981 has secured a second term. But Raisi has managed to threaten Rouhani's bid by seizing on concerns about the economy to run a populist campaign. The nuclear deal lifted international sanctions on Iran, but most Iranians have yet to feel the benefits, leaving Rouhani vulnerable.

AD

Raisi's “campaign and its populist economic message continues to score with poor and rural economies,” said Cliff Kupchan, chairman of the political risk firm Eurasia Group. “He continues to hit Rouhani's record on the economy.”

But while Raisi has gained some momentum — the result, observers say, of help from Iran's influential Revolutionary Guard — Rouhani remains the favorite. His campaign events have turned into massive rallies for reformist opposition leaders under house arrest, and has called for conservative leaders to allow more social and political freedoms.

Thursday marked the official end to the campaign, and Iranians head to the polls Friday. If no candidate reaches 50 percent, a runoff will be held on May 26.