AGUASCALIENTES, Mexico — If there is a case to be made for preserving Mexico’s status quo, the citizens of Aguascalientes would seem to be the ones to make it.
A new Nissan plant is hiring for the night shift, and trains loaded with mechanical parts clatter north to the Texas border and beyond. Factory jobs abound, the crime rate is low, and even in the long-neglected eastern heights, a glass-walled public swimming pool crowns a sloping ribbon of parkland.
But as the presidential election nears, the discontent driving voters in the rest of the country has spread even to Mexico’s central manufacturing belt, despite its buoyant economy. The national rage over corruption that is imperiling the governing Institutional Revolutionary Party has taken hold in Aguascalientes, and citizens who could once be counted on to vote conservatively now appear ready to flip.
That helps explain the changing political fortunes of Andrés Manuel López Obrador, the populist presidential candidate. In his last two runs presidential runs, Mr. López Obrador barely registered here. This time, newfound support from voters in regions like Aguascalientes appears to be adding to his lead days before the July 1 vote.
Mr. López Obrador, 64, a former Mexico City mayor, has been campaigning on a vow to bring down what he calls the “mafia of power” and to battle Mexico’s entrenched inequality. The promises go hand in hand: His government will recover billions lost to corruption and waste, he vows, and steer that money back into social programs.
It is an argument that resonates with Martín González, 53, a worker at a German-owned plant in Aguascalientes that makes engine parts. He said he planned to vote for Mr. López Obrador.
Government help does not reach the people who need it most, Mr. González said. “What we see is that the only ones who benefit these days are those who work in the government — they steal it all,” he said.
Mr. López Obrador’s opponents argue that his policies would drive Mexico back to the disastrous 1970s, when populist presidents borrowed, spent and stole billions, plunging the country into debt and hyperinflation.
Given their source, though, those warnings ring hollow to many Mexicans. President Enrique Peña Nieto, who is limited to a single term by law, has led a government many Mexicans now equate with corruption — one that awarded government contracts to cronies and turned a blind eye to governors now accused of pocketing tens of millions of dollars.
The president’s Institutional Revolutionary Party, known as the PRI, picked a technocrat, José Antonio Meade, as its candidate because he was untainted by scandal. But he appears to be lagging in third place.
The conservative National Action Party, or PAN, which governed Mexico for 12 years before Mr. Peña Nieto took office, has suffered its own scandals and was seen as ineffective during its time in power.
Mr. López Obrador has offered few concrete details about how he will fight corruption. But he has convinced many that he will put a stop to the impunity, among them his supporters at the unionized engine parts plant.
“To be a politician was to be untouchable,” said Alejandro de Jesús Peña Ibarra, 32, a co-worker of Mr. González’s. “But if you start to place limits, then they will learn that they are no longer emperors.”
Francisco Abundis, the director of the polling firm Parametría, argues that anger over corruption looms over every other campaign issue. “The perception is that something has been taken from you,” he said. “You don’t know how, or how much, but you feel it.”
That leads to the suspicion that anyone who has climbed up the ladder may have benefited from questionable help during the ascent.
“It’s no longer a question of whether I am doing well,” Mr. Abundis said, explaining why a protest candidate has advanced in a region that is relatively prosperous. It’s “how is the person next to me doing — and what is the reason for it?”
State polling is poor, but one estimate by the election site Oraculus suggests that Mr. López Obrador and the PAN candidate, Ricardo Anaya, are running about even in Aguascalientes.
“We want a change now,” said Ana María Andrade, 31, a mother of two girls whose husband works in the plant. “The others have had plenty of opportunity and they did not improve the country.”
Neither she nor any of her 12 brothers and sisters voted for Mr. López Obrador in the past. Now, Ms. Andrade said, most of her family have thrown their support behind him. “Everybody is tired of the same promises,” she said.
That fatigue seems to be driving others who have switched allegiances.
“We are aware that López Obrador isn’t coming to save the world,” said Rosa María Romero Centeno, 59, a retired kindergarten teacher. “We just simply would like to teach the other parties a lesson.”
Mr. López Obrador has won support from retired and current teachers, she said, who are suspicious of a five-year-old education overhaul they believe was intended to cut jobs.
Her husband, Eduardo Antuna Villanueva, 63, a retired government employee, said that the failure of rule of law prompted him to support Mr. López Obrador, although nobody else in his social circle agreed with him.
“It’s a step towards no longer being so corrupt,” Mr. Antuna said, brushing off the allegations that Mr. López Obrador would create chaos. “He has matured.”
Other remains unconvinced.
“How many times has he run and how many times has it gone badly for him?” said Misael Salazar Macías, 42, a farmer in Pabellón, a nearby municipality where the city’s sprawl gives way to rolling cornfields. Mr. Anaya’s promise to lower the cost of fuel won his vote.
Mr. Salazar’s wife, Rosa Elena Macías Ramírez, 43, is still undecided. “Governments come and go, come and go,” she said. “They always forget the countryside.”
Some voters believe that Mr. López Obrador will destroy the economy.
“He is a socialist, he has communist tendencies,” said Francisco Gutíerrez Jiménez, 72, who sells raw milk from canisters on his pickup truck and plans to vote for the PRI even though “all politicians are thieves.”
If corruption is the campaign’s overriding concern — along with security in the hardest-hit states — the economy is also a worry.
Beneath the surface in Aguascalientes, there is a sense that the economic boom is leaving workers behind. Across Mexico, real wages have stagnated over the past decade, according to a study by El Colegio de México, and Aguascalientes is no exception.
A unionized factory worker may earn as much as $20 a day including salary and other bonuses. Savings plans, profit-sharing, free transport, subsidized meals and other benefits add to the overall package.
All the candidates have acknowledged that Mexico’s wages are low, but it is Mr. López Obrador’s arguments that appear to have left the deepest imprint.
“López Obrador would open many doors for us,” said Juan Carlos Álvarez Pedroza, 42, a worker at the parts plant, which pays more than most of the city’s many factories. “People would be valued,” he said, and “there would be an opportunity for better salaries and better benefits.”
Viridiana Ríos, a global fellow at the Mexico Institute of the Wilson Center in Washington, said that despite breakneck growth driven by investment from global automakers in Aguascalientes and the surrounding Bajío region, there were warning signs that helped explain voters’ discontent. “We have confused the term development with the term economic growth,” she said.
Ms. Ríos said: “I think the most important focus of the Bajío has been the game of a race to the bottom, to offer the auto industry the best conditions — years of facilities and tax exemptions — with this goal of attracting more and more manufacturing.”
Instead, she said, “we need to bring the investment we want.”
Job growth is a magnet for migration from poorer regions of Mexico, but that depresses wages. One third of the state’s wages do not meet the government’s basic standard for well-being, Ms. Ríos said. That is up from about one-quarter two years ago.
And in an ominous indicator, the homicide rate in Aguascalientes doubled last year, although it is still very low compared with most of Mexico.
If Mr. López Obrador has finally found support in the conservative Bajío, his campaign faces one additional challenge; persuading some voters to pick any candidate at all.
“Anybody who reaches the presidency will do the same thing — steal,” said Erandi Rodríguez, 21, a stay-at-home mother with a 2-year-old daughter. Ms. Rodríguez said she had made up her mind to cross out her ballot to show her disgust.
“El Peje could make a change,” Ms. Rodríguez said, using Mr. López Obrador’s nickname.
She hesitated a moment. Then her default mistrust returned.
“But he’s not going to do everything he says he will,” she said.