MEXICO CITY — If Andrés Manuel López Obrador has his way, Mexican political life will soon get a whole lot stingier.

The front-runner to be the next president of Mexico says he will not live in Los Pinos, the lush and landscaped presidential palace, but turn the grounds into a public park.

He says he will not set foot on the $218 million presidential airplane — calling it an offensive “palace for the skies”— but sell the entire fleet of government planes and helicopters.

His salary will be less than half that of the current president, ­Enrique Peña Nieto. And the “luxurious” pensions of former presidents and their teams? López Obrador will slash them.

“Not even Obama gets that kind of pension,” he has said.

In Mexico, a country famously stained by corruption, López Obrador is running as Mr. Clean. This year, the political stars have aligned to his benefit — he has a commanding lead in the polls ahead of the July 1 vote — primarily because of outrage over corruption.

López Obrador has been a fixture on the Mexican left for decades, mostly as an agitator against the dominant parties and political elites, who fear his economic agenda and his tendency to rally the masses for his causes. López Obrador burnished his reputation for austerity during a stint as Mexico City mayor more than a decade ago, living in a modest apartment and driving a Nissan sedan — a stark contrast to many top Mexican politicians who live in mansions. His strategy for fighting corruption now, as then, is essentially to lead by example.

His administration, he says, will punish the fraudulent, slash perks of power and recoup the $25 billion in government funds he estimates is stolen every year, funneling it into development projects and social programs for the poor.

In a speech earlier this year, López Obrador said he wanted to “moralize public life.”

“We are going to get rid of the luxuries of government,” he said.

This approach, however, strikes many corruption experts as naive and misguided. When he promises to cut salaries of top officials, they see a policy that would encourage bureaucrats to supplement lost income in illicit ways. Civil society leaders say Mexico needs structural reforms to root out corruption, such as establishing an independent attorney general.

“López Obrador has not made any serious proposals about corruption,” said María Amparo Casar, executive president of Mexicans Against Corruption and Impunity, a nonprofit group. “To think that an individual at the top of the pyramid, the president, says by decree that this is going to disappear, when it’s a phenomenon that permeates the entire public administration, it’s difficult to believe.”

Even worse, some opponents see the candidate as a messianic strongman in the making, who would use the anti-corruption campaign to consolidate power or prosecute political enemies.

But López Obrador is riding a wave of discontent. Before the last election, many voters had hoped that by bringing back the Institutional Revolutionary Party (PRI) — which ruled Mexico from 1929 to 2000 — the government would restore order amid a raging drug war. Not only has violence gotten worse, but there has been a resurgence of the type of cronyism and graft that defined the party before Mexico’s transition to democracy.

Peña Nieto’s wife purchased a multimillion-dollar mansion from a government contractor. Emilio Lozoya, who helped run Peña Nieto’s campaign and then led Pemex, the state-owned oil company, has fought allegations that he received millions of dollars in bribes from a Brazilian construction giant. Several former PRI governors are facing corruption charges.

These scandals have hurt the chances of the PRI candidate, José Antonio Meade, who is running in third place in recent polls. Ricardo Anaya, who represents a right-left alliance, is second.

During Peña Nieto’s term, Mexico has fallen 30 rungs in Transparency International’s world corruption ranking, plummeting past countries such as Sierra Leone, Burma and Azerbaijan into the murky bottom quarter of the world’s most corrupt governments.

López Obrador insists that he is the man to change that.

“His primary achievement is that there is no one who can call him corrupt,” said Ricardo Monreal, one of his top campaign advisers. “They can call him crazy, a messiah, but nobody can say he is a thief.”

Window into leadership style

As a young man, López Obrador worked as an advocate for the indigenous in his home state of Tabasco, along Mexico’s gulf coast. He lived in a dirt-floored shack in a rural village with no electricity and helped oversee public works. He later worked with a federal consumer rights agency.

He joined the PRI but broke away to join a leftist party in the 1980s. He won the mayoralty of Mexico City in 2000, his only electoral victory.

This mayoral period offers a window into how he might put into practice his oratory about fighting the “mafias of power” in Mexico.

The municipal government that he inherited was riddled with corruption, according to several former members of his administration, who blamed years of PRI dominance. One of his top aides, José Agustín Ortiz Pinchetti, recalled touring vast warehouses filled with government-purchased chairs, apparently acquired only to provide kickbacks. He said that bureaucrats in the tax collection offices routinely siphoned off money.

“I saw unbelievable things,” Ortiz Pinchetti recalled.

Whether it was backroom deals with governors or payoffs to union bosses, corruption had been built into the way the PRI ruled Mexico for decades, a system intended to co-opt segments of society with benefits and perpetuate the ruling class. López Obrador’s message has long focused on breaking that system.

During his five-year tenure as mayor, López Obrador eliminated hundreds of jobs from the bureaucracy. He cut the salaries of his top aides and raised the pay of lower-ranking employees.

As part of his austerity push, city aides lost bodyguards, personal secretaries and government-issued cellphones. International trips and expense-account meals were cut back, former officials said.

“I had 65 advisers, and he reduced them to five,” said Ortiz Pinchetti, who served as government affairs minister for three years.

Aides described these measures as a way to free up money for social programs but also to present to the working-class poor — the backbone of López Obrador’s political support — an image of thrift. Those who have worked alongside López Obrador compare him to José Mujica, the former Uruguayan president, who lived on a ramshackle farm and donated most of his salary to charity.

López Obrador now lives in a middle-class neighborhood in southern Mexico City, next to a doctor’s office. On the campaign trail, he flies commercial.

“He’s very frugal,” said Marcelo Ebrard, who served as López Obrador’s police chief and later became Mexico City mayor. “He doesn’t like cars, watches.”

But López Obrador’s zeal to clean up government was also about establishing command, said Ignacio Marvan, an aide during his mayoral term.

“It’s not just morality. You can’t be an efficient and respectable government with these levels of corruption,” said Marvan, now a professor at CIDE, a research university in Mexico City. “You lose authority.”

López Obrador’s municipal administration was perhaps best known for popular social programs, including stipends for single mothers, the elderly and the disabled. These increased government debt, as critics often point out. But by the time he left office, he had balanced the budget.

López Obrador’s critics see him as an authoritarian who does not tolerate criticism by the media or civic groups. He has said he wants a plebiscite on his rule halfway through his term; critics note how such votes have been used elsewhere in Latin America to abolish term limits and undermine democratic institutions.

López Obrador’s anti-corruption proposals include establishing stricter penalties for conflicts of interest and corruption violations, and providing greater transparency into government contracting and finances. But on the stump, he mostly focuses on how he can battle corruption by example.

José Octavio López, who is on a citizens’ committee overseeing the Mexican government’s National Anti-Corruption System, said the idea that López Obrador is a “clean person and automatically things are going to change” is “total BS.”

What is important, he said, are structural changes — like creating an attorney general’s office outside the executive branch.

“What we need are institutions that really are independent,” he said.

Scandals in his own ranks

As mayor, López Obrador was not able to eradicate corruption in city government.

In early 2004, his finance secretary, Gustavo Ponce, was accused of being involved in the disappearance of $3 million in government funds. López Obrador fired Ponce, who was later sentenced to eight years in prison but was released early after a judge ruled that there was a lack of evidence.

In another case, René Bejarano, a member of the city’s legislative assembly and former personal secretary to López Obrador, was caught on video taking $45,000 from a businessman who had won city construction contracts. López Obrador was criticized for blaming the scandal on a conspiracy by political rivals. Bejarano spent eight months in prison before a judge threw out the corruption charges against him.

While López Obrador was not implicated personally in wrongdoing, the scandals tarnished his government’s image.

“He has a reputation as an honest man, but his administration was marked by corruption scandals,” Casar said.

During the campaign, López Obrador has been criticized for naming people dogged by corruption scandals to his team, including a former mining union leader accused of embezzlement. The candidate has responded that he is seeking reconciliation and national unity.

Many López Obrador supporters acknowledge that it will be next to impossible for him to eradicate corruption in Mexico. But they hope he will mark the beginning of a real change.

“How much time is it going to take? Many years. One or two generations,” said Marcos Fastlitch, a prominent businessman who supports López Obrador. “But the longer we wait to start, the longer it will take to clean up.”

Gabriela Martinez contributed to this report.