Continued from page 2

On Sunday, the largest march so far was held in Mexico City, where 90,000 people, including some well-known performers, protested hours ahead of the last scheduled presidential debate. Next on their agenda is a face-to-face debate with candidates in the coming week, an invitation Mr. Pena Nieto has declined.

Outside Mexico City, in the town of Chicoloapan, part of a state where the leading candidate served as governor until last year, a narrow street welcomed motorists with a ceramic statue of Jude the Apostle, the saint of lost causes.

For Alejandro Velazquez Ruiz, 26, the negative publicity surrounding the front-runner hit home. Mr. Velazquez is unemployed, lacks a college education and plays soccer to make money.

“They were all leaning toward Pena Nieto, but now we see all the bad things they say about him,” said Mr.Velazquez, who quit his job in the capital because he had to work seven days a week for $500 a month as a mortgage lender.

“We started to have questions. Now I’m voting for Andres Manuel Lopez Obrador.”

In Texcoco, another town outside Mexico City, 19-year-old Gamaliel Pacheco will back the favorite.

Mr. Pacheco was only 7 when the PRI lost power after decades of continuous rule marked by rigged elections, corruption and patronage jobs.

“The time PAN was in power, there were a lot of deaths,” he said. “When PRI ruled, we didn’t see that.”