Andres Lopez Obrador Image Credit: Reuters

MEXICO CITY: Standing before a roaring crowd in Mexico City at the launch of his presidential campaign, candidate Ricardo Anaya seethed with anger.

“In the last weeks … there have been all kinds of lies,” he said. “From here on we tell the government and the authors of this dirty war that the more resistance we face, the more force we’ll take off with.”

Mexico’s election campaign opens this weekend, freeing the four candidates who have qualified for the July 1 vote to register with the government and start spending heavily on advertisements. But the race _ and the drama _ have been heating up for months.

In November, polls had Anaya tied for first place with leftist populist Andres Manuel Lopez Obrador, a three-time presidential candidate and former mayor of Mexico City who is one of the country’s best-known political figures. Trailing them were Margarita Zavala, the wife of former president Felipe Calderon, and Jose Antonio Meade Kuribrena, from Mexican President Enrique Pena Nieto’s Institutional Revolutionary Party.

Anaya, a former senator from the centre-right National Action Party, had ascended quickly, thanks in part to his scathing criticism of Pena Nieto and his risky pledge to investigate allegations of graft by the president and his party.

Until the smear campaign began.

In February, Mexico’s attorney-general, a Pena Nieto appointee, announced he was investigating a property deal involving Anaya, saying the candidate was suspected of laundering money.

Independent investigations into the deal have concluded that Anaya likely broke no laws when he bought and sold a plot of land in an industrial park in his home state of Queretaro. A group of public intellectuals _ not all of whom are Anaya supporters _ signed a letter imploring the government to stop politicising law enforcement.

But the investigation has continued, staining Anaya’s image as an anti-corruption crusader and significantly reshaping the race. As support for Anaya has slipped from 30 per cent to 24 per cent, Lopez Obrador has surged. He now has a double-digit lead over Anaya, with 42 per cent support.

The impact of the investigation on Anaya’s campaign shows what an important issue corruption is for many Mexican voters, who are incensed after a seemingly unending string of scandals involving governors, cabinet ministers and other allies of Pena Nieto. A recent poll by the Reforma newspaper found that 47 per cent of voters “would never vote” for his PRI party or its candidate, Meade.

Analysts believe Lopez Obrador has surged in part because voters view him as a clean candidate who has not been targeted by corruption allegations. They have flocked to him in large numbers despite warnings from the right that his economic proposals could lead Mexico toward a fate like Venezuela’s.

While his opponents have sought to paint Lopez Obrador as a reincarnated Hugo Chavez, the socialist who led Venezuela until his death in 2013, his politics look more like those of former US presidential candidate Bernie Sanders.

Lopez Obrador has proposed rolling back or modifying efforts pushed by Pena Nieto to open the energy sector to foreign investment, and he has criticised the North American Free Trade Agreement, which is being renegotiated with the United States and Canada.

While Mexican markets have greeted his rise warily, many voters appear happy to risk uncertainty, said Carlos Bravo Regidor, a political analyst and a professor at CIDE, a public research centre in Mexico City.

“Mexicans want change, and anger is trumping fear,” Bravo said. “This election is not about platforms, or issues, or even experience. This is about who has the credibility to make change.”

Bravo said Lopez Obrador has been softening some of his more controversial stances, which also helps.

“I guess he has learnt,” Bravo said. “He’s clearly coming to terms with the fact that Mexican voters are more conservative than he would like.”

One issue on which Lopez Obrador has been tamer this time around is corruption. In a recent interview, he said he would tackle corruption, but would not spend energy prosecuting Pena Nieto or his allies. “I am not going to put the president in jail,” he said.

Those kinds of promises have led some to question whether Pena Nieto’s party targeted Anaya in part because it fears him more than Lopez Obrador. Some have even suggested that there may be an alliance between Lopez Obrador and the PRI.

Bravo said he thinks Lopez Obrador is just playing it safe.

“As a candidate, he has more to lose than to win,” Bravo said. “Maybe Pena Nieto and Lopez Obrador just realised they don’t have a lot to gain in fighting each other.”

Lopez Obrador has not spoken out against the investigation into Anaya, even as the attorney general in the investigation, Alberto Elias Beltran, has come under fire.

The Anaya case isn’t the first time Beltran has been accused of acting more like a political operative than a prosecutor.

In March, Beltran chose not to file money-laundering and tax fraud charges against Cesar Duarte, a former PRI governor from the state of Chihuahua, despite ample evidence that Duarte had diverted state funds.

Last year, Beltran fired the investigator looking into suspected bribes paid to the Brazilian construction firm Odebrecht by Emilio Lozoya, a Pena Nieto ally who worked on his 2012 presidential campaign. A federal judge recently suspended the inquiry.