While elections in Iran look like slug-it-out campaigns, with many of the trappings of competition -- government critics, disagreement on high-profile issues, and televised public debates -- they are kept tightly in check by unelected officials under the country's clerically dominated system.

There is careful vetting by the Guardians Council, which routinely disqualifies all but a small fraction of reform-minded candidates. Entrenched hard-liners within the Islamic Revolutionary Guards Corps (IRGC) and its volunteer-based paramilitary, the Basij, and Friday Prayer leaders in pulpits throughout the country also combine to stake out no-go zones. Nevermind the supreme leader, who has the final say on political, military, and religious affairs, and his network of representatives at all levels of government.

But in addition to these hallmarks of political power struggles in postrevolutionary Iran, there is also a state-dominated media environment with a history of subtle attacks on candidates and sitting officials, including incumbent President Hassan Rohani.

Attacks and smears targeting elected officials -- in the past and so far in the run-up to this election-- have included crackdowns on supporters, intrigue around family members, and appeals to national security.

Rohani, who is allied with Iran's reformers and centrists, faces a potentially strong challenge in the May 19 election from hard-line cleric Ebrahim Raisi. But another conservative, Tehran Mayor Mohammad Baqer Qalibaf, also waged harsh attacks on the incumbent before dropping out of the presidential race on May 15.

Here's a look at some of the issues that have emerged as hard-liners try to unseat a man they've criticized as being too friendly toward the West.​

Targeting Close Aides, Associates, And Relatives

This tactic has been used by hard-line officials against politicians who oppose them, but also against perceived enemies from other walks of life.

Iranians whose close associates or family have been targeted in the past include Nobel Peace Prize-winner Shirin Ebadi. She recounted in her 2016 autobiography from exile, Until We Are Free: My Fight For Human Rights In Iran, how Iranian security agents hauled her sister off to jail in the middle of the night or tricked her husband into cheating on and denouncing her in order to exert pressure on her.

Presidents whose allies have come under attack have been largely helpless to protect them.

This year, in the first of three televised presidential debates, Qalibaf accused Rohani of relying in part during his victorious 2013 campaign on an individual who has since been sentenced to death for economic corruption. Qalibaf did not name any names, but he appeared to be referring to Iranian billionaire and business magnate Babak Zanjani. His accusation echoed a statement in January by the head of the powerful judiciary, Sadegh Larijani, who said Zanjani had claimed that he had contributed to Rohani's election campaign.

Rohani denied the accusation as a "sheer lie."

"A corrupt individual who is sentenced to death has made a claim. One doesn't quote a corrupt individual," Rohani said in the April 28 debate.

Hard-line news sites published a photo of Rohani giving what appears to be an award to Zanjani. Rohani has countered that the image is from an event held several years ago to highlight Iran's top exporters. He said he was asked to present the awards, saying that he didn't know the recipients.

During the second presidential debate, on May 7, Qalibaf accused the daughter of Rohani's education minister of the "smuggling of imported goods." The allegations were also leveled by a spokesman of the judiciary, who said in late April that a large shipment of clothing had been discovered in a minister's home.

Vice President Eshaq Jahangiri, who is one of the five men running against Rohani but who is seen as in the race to run cover for the president, dismissed the charges, saying that the minister's daughter had paid all custom duties.

Months before the presidential campaign, Rohani came under pressure over his brother, Hossein Feridun, who is a member of the president’s inner circle. Feridun has been accused of criminal wrongdoing. In January, 46 lawmakers called on Rohani to present his brother, a former ambassador to Malaysia, to the powerful judiciary to face "financial corruption charges." Reports had swirled that Rohani might be getting "pressured to part ways with his younger brother," who was said to be a key contributor to Rohani's 2013 campaign and has been dubbed the president's "eyes and ears."

"Feridun's fate -- whatever it is -- will also affect the political fate of Rohani," the daily Arman predicted in April. ​

The opposition website Sahamnews.org in May quoted unnamed sources as saying that Supreme Leader Ayatollah Ali Khamenei had warned Rohani about Feridun and the president's chief of staff, Mohammad Nahavandian, and called for their dismissals.

During the third presidential debate, on May 12, Raisi and Qalibaf each tried to paint Rohani with the corruption brush.

"The head of the government is being told that the closest person to him is engaged in corruption," Raisi said, adding that Rohani has been resisting calls for action.

It's not just Rohani. Two of his presidential predecessors, hard-liner Mahmud Ahmadinejad and reformist Mohammad Khatami, experienced similar broadsides-by-association.

Ahmadinejad, a divisive hard-liner who served two terms as president from 2005 to 2013, was targeted over his inner circle. Close Ahmadinejad aide Esfandiar Rahim Mashaei was once accused of being part of a "deviant current" straying from the principles of the Islamic establishment. Several individuals close to Mashaei were even arrested and charged with sorcery in 2011, at a time when the president was reportedly coming under increasing criticism from Khamenei. Mashaei also came under pressure when a $2.6 billion embezzlement scandal rocked the country, accused of ties to the mastermind of the massive fraud case.

Khatami, who campaigned on reform and held the presidency from 1997-2005, also witnessed attacks on his supporters and allies, including civil-society activists and journalists who were harassed, summoned, detained, or imprisoned. Two of Khatami's key associates -- former Tehran Mayor Gholam Hossein Karbaschi and leading reform voice and onetime Interior Minister Abdollah Nuri -- were eventually tried and jailed for corruption and political and religious dissent, respectively. Khatami political strategist and consultant Said Hajarian became the victim of an assassination attempt in 2000 that left him partially paralyzed and in need of constant medical care.

'Threat To The Islamic Republic'

Hard-liners often accuse their rivals of undermining the Islamic establishment and the values of the 1979 revolution, seemingly highlighting their concern that their dominance over the country's political landscape could diminish. Scores of intellectuals, journalists, activists, and human rights defenders have been harassed and jailed on vague charges that include "acting against national security" or "harming Iran's national interests."

Presidents have been also accused of undermining the clerical establishment.

Khatami -- who endorsed Rohani in a video released on May 14 -- was accused during his own presidency of being Westernized and of damaging the Islamic republic over his attempts at reform, although he served two terms.

Well to his right on the political spectrum, Ahmadinejad was made out by some to be a potential threat for repeatedly defying the aging supreme leader, Khamenei.

And Rohani has repeatedly been targeted over his attempts at engagement with the West, prompting warnings of alleged Western "infiltration" efforts aimed at undermining the Iranian establishment.

In the second presidential debate, Raisi accused Rohani's government of weakness during negotiations with world powers ahead of the landmark deal exchanging curbs on Tehran's nuclear program for relief from sanctions.

At a rally for Raisi in the capital, an organizer referred to Rohani's government as "the government of humiliation." "Mr. Rohani, how quickly you shook hands with the enemy," the organizer said, according to a report by the Financial Times.

Pictures posted by the Tasnim news agency showed some of Raisi’s supporters holding handwritten signs that said: "We've come here to put an end to the green light to the enemy."

Rohani aides have also been accused of improper affiliations with Western countries, a claim the Iranian president has dismissed as a misuse of the term "infiltration" for their political goals.

The harassment and arrests of dual nationals -- including Iranian-Americans accused of espionage -- are seen as further evidence of efforts to bring Rohani's outreach efforts to heel.

Speaking on March 15, the commander of Iran's Islamic Revolutionary Guards Corps (IRGC), Mohammad Ali Jafari, warned against pro-Western and liberal tendencies among state officials.

"Today, many of the officials running the country have liberal, Western, and counterrevolutionary views," he said.

Jafari did not single out by name Rohani, who has a doctorate in constitutional law from Glasgow Caledonian University, or any of the members of his cabinet, some of whom are graduates of American universities. But he complained that some officials appeared proud of having obtained their degrees or doctorates from Western universities.

The Economy And The Nuclear Deal

Rohani came to power in 2013 promising Iranians a better economy, among other things. Many Iranians were hoping that ending their dispute with the international community over Tehran's nuclear program -- in the end, the deal with the United States and other major powers in 2015 to trade curbs for an end to sanctions -- would bring them significant economic benefits. Yet among other sticking points, including a new U.S. president who has vowed to renegotiate the nuclear deal, many firms still appear reluctant to do business with Iran. Supreme Leader Khamenei and hard-liners have complained publicly that Iranians have not seen tangible improvements in their daily lives.

Rohani confronted increased pressure during the current campaign to demonstrate any windfall from the nuclear agreement, primarily from Raisi and Qalibaf.

"Today, 30 percent of our young people are out of jobs and unemployment is over 12 percent," Raisi said during a recent rally in Tehran. "Does this situation have to continue? Do we have to wait for foreigners to fix our problems?"

WATCH: Is Iran's Presidential Election Free And Fair?

Speaking on state television on May 1, Qalibaf played down Rohani's role in achieving the deal. He said that any other administration would have signed the nuclear accord because the green light for the nuclear talks came from "the entire establishment." But he also said Rohani's government has failed to translate the deal into benefits for Iranians.

"Have people benefited from the accord?" he asked, adding that "this is a serious weakness" of Rohani's government.

On a related note, Rohani has also come under pressure for allegedly doing too little to implement Khamenei's call for a "resistance economy" to make Iran more self-sufficient. His rivals have suggested that the president has been relying heavily on foreign investment while ignoring national resources and capabilities.

In fact, Khamenei personally called out Rohani on that subject in early March.

"Of course, the government has taken remarkable steps," Khamenei was quoted by state TV as saying, "but if the resistance economy had been implemented fully and widely, we could witness a tangible difference in people's lives."

The same week, Guardians Council head Ayatollah Ahmad Jannati called on Rohani to present evidence of the degree to which such a resistance economy has been put in place. "If some work has been done, let people know so that they can rejoice," Jannati said. "If not, apologize to the people and explain why nothing has been done."

Khamenei later criticized the government's economic policies in his Norouz message, when he repeated his call for more jobs and greater self-sufficiency.

Official Graft

Rohani has also come under pressure over leaked pay slips that suggested senior government employees received salaries that were as much as 200 times what more modestly paid government employees make. Several officials were reportedly dismissed over the scandal and the government said it is taking steps to regulate the salaries. Yet the president's rivals have used the issue repeatedly to pressure him.

Speaking on March 6, former Iranian nuclear negotiator and onetime presidential candidate Said Jalili blasted the government over what he described as "astronomical salaries." Jalili said that employees outside those privileged, highly paid few are being told to be patient in the face of economic problems.

Rohani's associates had said ahead of the presidential campaign that the leaks were aimed at diminishing his chances of reelection.

In another context, Ahmadinejad was criticized for reportedly taking large delegations, including family members, with him during his annual trips to New York to attend the United Nations General Assembly. His 2012 delegation reportedly included over 100 people.

In Iran, where officials and politicians frequently go to great lengths to demonstrate piety and modesty, signs of conspicuous consumption can do considerable damage.

In 2013, Guardians Council head Jannati said that the country's next president should lead a simple life and not drive around in a Mercedes. Jannati did not name names, but he appeared to be referring to former President Akbar Hashemi Rafsanjani, who had arrived to register for the presidential vote in a Mercedes. Rafsanjani, who died earlier this year, was banned from running.

Preelection Crackdown

Ahead of voting, hard-liners frequently resort to crackdowns to tighten their grip on power and undermine a sitting president by demoralizing his supporters.

In recent months, at least three journalists, a well-known editor, and several administrators of pro-government and reformist Telegram channels have been arrested, prompting warnings over a crackdown.

On March 15, lawmaker Ali Motahari disclosed that 12 administrators of Telegram channels had been arrested by a "military intelligence body." He said the arrest created "doubts" about the upcoming vote.

Another outspoken lawmaker, Mahmud Sadeghi, also expressed concern in a letter to IRGC commander Jafari. He said that the arrests, which he said appeared to have been carried out by the IRGC's intelligence unit, had created worries in the Iranian society.

Iran's judiciary also blocked correspondence on the highly popular Telegram messaging app. Instagram Live was reportedly also blocked following an order from authorities within the judiciary.

Iranian authorities have stepped up their repressive measures in the run-up to past elections. In 2013, for instance, a number of activists were either arrested or summoned for questioning. Some journalists previously released on furlough were also recalled to prison in the month leading up to the voting.