[Breaking news update, Friday, 11:50 p.m. ET]
Iran's Supreme Leader, Ayatollah Seyyed Ali Khamenei, cast the first ballot in the country's presidential election on Friday morning. His vote marks the opening of the polls.
[Original story, posted Wednesday, 4:37 a.m. ET]
What's at stake in Iran's presidential election?
(CNN) -- More than 50 million Iranian voters are eligible to go to the polls Friday to pick a new president.
The country, a regional power player, faces a painful economic situation, resulting in part from international sanctions intended to pressure Tehran over its foreign policy stance and its nuclear program
The last presidential election, in 2009, sparked allegations of massive fraud and a protest movement that was subsequently crushed by the government of the re-elected President Mahmoud Ahmadinejad.
Friday's presidential vote thrusts Iran's democratic process back into the spotlight. But a question mark hangs over how much of a difference its outcome can make to the Iranian people.
How democratic is Iran's election process?
Iranian citizens ages 18 and over, male and female, can vote for the president, but only an Iranian-born male Shiite can run for president, said Alex Vatanka of the Washington-based Middle East Institute.
Those who want to stand have to be approved by Iran's Guardian Council, a non-elected body made up of six clerics and six lawyers operating under the oversight of the Supreme Leader Ayatollah Ali Khamenei. That means only candidates who have Khamenei's blessing can really contest the election, said Vatanka, making it "very much a limited, controlled process."
Khamenei "has four significant tools to weaken democratic institutions," and over time he has used them to sap the power of the president and parliament, said Mehdi Khalaji, a senior fellow at the Washington Institute for Near East Policy.
First, the judiciary are accountable to him and listen only to him, he said. The country's intelligence apparatus also answers to the Supreme Leader, as does Iran's military; he is commander-in-chief. Khamenei also pulls the strings when it comes to state-run TV and radio, allowing him to control the flow of information.
"Each election, he makes sure that all those who may cause problems for him or challenge his authority won't be qualified," Khalaji said, which means the outcome is effectively "pre-set."
The other obstacle to democracy is fraud, said Vatanka said, citing the disputed 2009 election.
The Guardian Council and Interior Ministry will be the chief bodies monitoring the vote, he said.
Who's running for election?
The Guardian Council approved eight candidates to run in the election, out of more than 680 who registered, but two of those dropped out of the race this week. The six remaining are: Mohammad Bagher Ghalibaf, Ali-Akbar Velayati, Saeed Jalili, Mohsen Rezaei, Hassan Rouhani, and Mohammad Gharazi.
Velayati, Ghalibaf and Jalili, who is Iran's chief nuclear negotiator, are all seen as being close to the Supreme Leader and would be unlikely to challenge his authority, said Khalaji.
The two who dropped out are Mohammad Reza Aref and conservative Gholam-Ali Haddad-Adel, who had not been polling strongly.
Aref, who was vice president to former President Mohammad Khatami, was seen as a reformist candidate. Khatami said he was backing Rouhani, seen as a centrist, and that Aref had withdrawn "to increase the reformist camp's chances of winning," according to Iran's state-run Press TV.
Rouhani did better than Aref in the presidential debates and seems to have the top guns behind him, including former president and political heavyweight Akbar Hashemi Rafsanjani, Vatanka said. One of the two had to drop out so the reformist camp would not split its vote, he added.
However, those voters who backed Aref will not necessarily back Rouhani, said Khalaji.
In a blow to Ahmadinejad, his aide and protege Esfandiar Rahim Mashaei was among those excluded from standing by the Guardian Council. Another high-profile figure barred from the race was Rafsanjani.
What's the difference between Iran's president and the supreme leader?
The Supreme Leader Ayatollah Khamenei holds many of the cards and, as an unelected individual, can claim the greatest share of power. He directs foreign policy and has a degree of economic control too.
Iran's president is the country's highest official after the supreme leader and is responsible "for implementing the Constitution and acting as the head of the executive, except in matters directly concerned with (the office of) the Leadership."
The president has a lot of sway over economic issues but not full control, said Khalaji.
Khamenei has sought to present himself as a religious figure who is above politics, said Vatanka, but his actions have betrayed his agenda. "He tends to opt for policies which are conservative and almost always about protecting his power," he said.
Iran has an elected parliament, but it does not play a significant role in deciding strategic issues such as foreign policy, said Vatanka, although it does pass a budget.
The Guardian Council again plays a role in approving parliamentary candidates, and lawmakers have seemed keen to support the supreme leader since he and Ahmadinejad fell out, he added.
"There has been a power grab over the past few years by Khamenei, and that has come at the expense not only of the president but of Parliament," Vatanka said.
What happened in 2009?
Ahmadinejad, who had Khamenei's backing, found himself in an unexpectedly close and polarized race with reformist candidates, including Mir Hossein Moussavi. People were so excited they rallied in the streets across the country, and the voting seemed set to go to a second round, Khalaji said.
However, Ahmadinejad won re-election with 62.63% of the vote, according to Iranian government sources. His nearest rival, Moussavi, received 33.75%. Demonstrations protesting the outcome of the election broke out across Tehran. Dozens of people were reported killed. Despite widespread unrest, Ahmadinejad's re-election was formally certified by the Guardian Council.
The Green Movement, the opposition force that exploded onto the scene during the 2009 elections, was later crushed by the regime's security apparatus. Moussavi and another opposition leader, Mehdi Karoubi, remain under house arrest.
Dozens of political activists are still in prison, and others who were released live under restrictions, Khalaji said.
Iran's security officials have warned the public against anti-government street protests this time round.
No independent investigation was allowed, said Vatanka, and the extent of the fraud that took place in 2009 remains unknown.
How is this election expected to differ from others?
The Supreme Leader learns from past mistakes, but Iran is a big country and its politics are unpredictable, said Khalaji. Polls he has seen predict just over half the country's voters will cast their ballot, which would be the lowest turnout since the Islamic Republic of Iran was established in 1979.
The outcome depends in part on whether the middle class comes out to vote in big numbers, Khalaji said.
However, the people who vote are are mostly organized by the government -- some 15 million of them, said Khalaji. The organization is done through the religious network of mosques and the loyalist Basij militia, particularly in small towns and rural areas, he said. Municipal elections will also be held Friday, which could also bring people to the ballot box.
The presidential election could well go to a second round this time, said Khalaji.
There is no sign of the same excitement that galvanized the Iranian people before the 2009 election, said Vatanka, but there have not been wide calls for a boycott either. Although Rouhani is not beloved by the reformist camp, they may rally behind him as their best option rather than see the hardliners' preferred candidate elected by a big margin, he said.
"Iranian public opinion is deafeningly silent, a silence that even the media close to the regime has complained about," Ali Reza Eshraghi, Iran's Project Manager at the Institute for War and Peace Reporting, said in a commentary for CNN.com.
"Unlike the four previous presidential elections during which the streets were turned into lively and colorful carnivals with the supporters of different candidates engaging in unending debates and fervent speeches, this time it is only the walls of the streets that have been covered with banners and posters."
How will the election outcome affect Iran's international relations?
Foreign policy is designed and implemented by the Supreme Leader, not the president, said Khalaji. As a result, the change of president will do little to influence foreign policy directly.
Eight or 16 years ago this wouldn't have been the case, said Khalaji, but the old elites and factions have been largely sidelined, and a new generation of politicians totally loyal to Khamenei has taken their place.
Once the new president is elected, he may try to play hardball with Khamenei, as Ahmadinejad did in the last few years, said Vatanka, but the Supreme Leader will want to keep control of anything sensitive. That could be expected to include Iran's positions on Israel, Syria and its controversial nuclear program. Tehran insists its intentions are peaceful, but the West suspects it of seeking to develop nuclear weapons.
The best the West can hope for, said Vatanka, is that Khamenei uses the election of the new president as a way to shift course slightly without losing face. However, Iran is unlikely to give up a nuclear program it has been pursuing for decades, no matter what the external pressure.
"At the same time, if we have a new face in the presidential palace in Tehran, that can become a catalyst for a new phase to begin between Iran and the world," Vatanka said.
Recent talks between Iran and world powers on the nuclear issue have made little progress. The United States has sought to pile on the pressure by imposing sanctions on Iran's petrochemical industry, its automotive industry and its unit of currency, the rial. Other Western nations have also imposed sanctions on Iran.
What are the major issues for the electorate?
The biggest issue for voters is the country's economic situation, said Khalaji. The economy is in a bad way for three reasons, he says: massive corruption within government, mismanagement and the painful international sanctions.
"The problem is that candidates can promise to people to improve the management and beat the corruption, but they cannot promise to change the foreign policy which led to sanctions, and that creates a dilemma for anyone who wants to be president this time," said Khalaji. "The executive power suffers from the foreign policy but has little role in shaping it."
A change in foreign policy, and specifically U.S.-Iran relations, is seen by many voters as central to improving their everyday life because of the international sanctions, which are so closely intertwined with the economic situation, said Vatanka.
Iranians have grown used to living with corruption, mismanagement and restricted freedoms over the years, he said, but the sanctions are causing new pain by hitting ordinary people in the pocket and causing shortages of everyday goods. The rial has plunged, inflation is running at over 35%, unemployment is rising and oil revenues dropped by half last year because of sanctions.
This has bred a great desire for change, Vatanka said.
"But the question at the heart of the matter is, does the average Iranian believe that voting matters any more?" he said."If you don't believe it matters, you can be as angry and disillusioned as you want, but you are not going to drag yourself to the ballot box."
Will the election change anything for the Iranian people?
If one of the candidates close to Khamenei wins the election, little is likely to change in the cultural or social arena, said Khalaji.
Ghalibaf, currently serving his second term as mayor of Tehran, is as hardline as Ahmadinejad when it comes to social and Islamic issues, he said. "But it's very obvious that his economic management is much better than Ahmadinejad's."
The other candidates seen as close to Khamenei have held political rather than senior management roles, he said, so it's hard to judge.
Essentially, said Vatanka, what follows the election will depend on more on what Khamenei and his people consider necessary to lessen the pain of sanctions than on who wins.
"It could be an opportunity for Khamenei to soften the Iranian position without being associated with that softening necessarily," he said of the vote.