NAUCALPAN, Mexico - Middle-class voters like Gerardo Olivo helped drive Mexico's ruling party from power 12 years ago, ending its seven decades of rule.
Now the same voters seem ready to bring back the party everyone knows as the PRI.
Olivo, 33, a financial trader, said he voted for the now- governing National Action Party in the past two presidential elections, hoping it would transform Mexico. He's fed up now, though. "My position today is to go back to the PRI," he said.
The PRI - or Institutional Revolutionary Party - held a strong lead in all of the final, major pre-election polls on Wednesday, counting on the very thirst for change that led voters …