MEXICO CITY _ Millions of Mexican voters go to the polls Sunday in closely watched state elections that will provide a critical preview of presidential balloting scheduled for next year.
Gubernatorial elections are taking place in three states _ the northern border state of Coahuila; the small western state of Nayarit; and, most significantly, in the sprawling state of Mexico, the country's most populous and politically significant entity.
In addition, citizens of Veracruz are electing more than 200 mayors amid widespread discontent with rampant crime and massive corruption in the oil-rich state along the Gulf of Mexico.
Sunday's showcase contest, however, is in Mexico state, where a bitterly fought battle featuring allegations of dirty tricks and smear tactics is widely viewed as a bellwether for next year's presidential contest, with broad ramifications for the country's long-term political scene.
The long-dominant Institutional Revolutionary Party, or PRI, has never lost a governor's seat in Mexico state since the party's founding in 1929 after the tumult of the revolutionary era. But on Sunday, the PRI faces a stiff challenge in Mexico state, which surrounds Mexico City, the capital, on three sides and is the home turf of President Enrique Pena Nieto.
The president approaches the final year of his single, six-year term as a greatly diminished figure _ deeply unpopular in polls and suffering broad citizen dissatisfaction with rising crime, corruption and sluggish economic growth.
Consequently, Sunday's vote in Mexico state is also emerging as a referendum on the future of the PRI, which regained the presidency in 2012 with high hopes for a resurgence after losing the top post in 2006 and 2000 to the conservative National Action Party.
Many analysts have predicted that a loss for the PRI in the state of Mexico _ home to more than 11 million voters, about as many as the U.S. state of Texas _ would doom the PRI's chances in next year's presidential race.
"The state of Mexico is the support base of the PRI, and if it loses there it will be in a worse position than ever," said Jose Antonio Crespo, a political analyst. "If it loses in its bastion, the PRI could face a collapse."
Looming over the race is Andres Manuel Lopez Obrador, 63, a fiery left-wing populist and twice-unsuccessful presidential aspirant who is gearing up for a third run next year. He is not a candidate in Sunday's balloting. But "Amlo," as he is known, after his initials, has been a prominent and contentious figure in the Mexico state campaign.
In rallies, Lopez Obrador has publicly called for the "transformation" of Mexico, lumping existing political parties (except his own) into what he labels the "mafia of power."
The skilled orator has also seen his political fortunes rise with the election of U.S. President Donald Trump, whom he has accused of mounting a "campaign of hate" against Mexicans.
Lopez Obrador heads the left-wing National Regeneration Movement, known as Morena. A victory for Morena in Mexico state on Sunday would probably cement Lopez Obrador's front-runner presidential status, even though major parties have yet to name their nominees.
Polls in Mexico state show a tight, two-person battle in the governor's race between the Morena candidate, Delfina Gomez, 54, a former schoolteacher and local mayor, and the PRI hopeful, Alfredo Del Mazo Maza, 41, a ruling-party stalwart.
Surging in recent polls is Juan Zepeda of the left-leaning Party of the Democratic Revolution, a former mayor of the gritty suburb of Ciudad Nezahualcoyotl. The resume of the charismatic Zepeda features a singular attribute: He says he lived in the United States illegally for years, an experience shared by millions of Mexican citizens.
The race has featured allegations of electoral improprieties from various candidates and parties. Without offering many specifics, all office-seekers have vowed to reduce crime, improve decrepit infrastructure and public transportation and increase benefits for the poor and working-class multitudes who comprise the vast majority of the state's population.
The PRI has geared up its immense electoral machinery on behalf of its gubernatorial candidate, Del Mazo. Party loyalists are referring to June 4 as "D Day," reported the magazine Proceso.
The PRI has long been adroit at corralling votes via handouts, patronage posts, job-generating public works projects and other strategies.
The PRI-led central government has denied opposition allegations of improper use of public personnel and funds in the Mexico state electoral campaign.
A narrow victory by the PRI candidate in Mexico state could spur appeals and protests from Lopez Obrador, who alleges he was cheated out of presidential victories in 2006 and 2012. In 2006, after his razor-thin loss, Lopez Obrador's irate supporters practically shut down Mexico City for weeks.
