Presidential candidate Andrés Manuel López Obrador, of the MORENA party, gives a thumbs up to supporters at the end of his closing campaign rally at Azteca stadium in Mexico City on  June 27. Mexico’s four presidential candidates are closing their campaigns before the country’s July 1 elections. (Ramon Espinosa/AP)

On July 1, Mexico will almost certainly begin a radical transformation — one that has gone almost completely unnoticed in the U.S. That’s because the most important outcome of that day’s national elections will not be who wins — but who loses.

Leftist reformer Andrés Manuel López Obrador will almost certainly capture the presidency. But the impending collapse of the Institutional Revolutionary Party (PRI) — whose candidate José Antonio Meade is expected to go down in an embarrassing defeat — will have even more impact. After nearly 90 years as the country’s dominant party, the PRI seems almost certain to suffer a historic defeat. Its collapse will dramatically remake the Mexican political landscape.

A brief history of the PRI

The PRI was the official party of the country’s 20th century authoritarian regime. As Mexico democratized over the past twenty years, the PRI proved remarkably resilient. Even after losing the presidency in 2000, it retained significant influence, and recaptured both the executive and legislative branches of government in 2012. Nationwide, it still controls 57 percent of city halls.

Yet the coming elections may well mark the end of the PRI as we know it. Not only is the party set to lose the presidency, but also approximately 70 percent of its congressional seats and possibly two governorships. This dramatic and rapid decomposition will have profound implications for the future of Mexican politics.

Why is the PRI collapsing now?

The PRI’s obituary has been written before. Resounding defeats in 2000 and 2006 seemed to augur the end, yet the party endured and rebuilt. This time seems to be different. The party’s breakdown in 2018 is extensive and far-reaching, combining overwhelming popular repudiation of the party’s brand and the deterioration of its internal machinery.

The most obvious factor for the PRI’s rapid decline is a generalized rejection of the party. Current president Enrique Peña Nieto’s administration has been an embarrassing disaster, overseeing spectacular corruption scandals and staggering violence. Unsurprisingly, a Reforma magazine poll found only 17 percent of Mexicans think the PRI should continue to govern the country.

At the heart of the PRI’s collapse, though, is the decline of the voto duro, the “hard vote” provided by local machinery. The PRI depended on leaders of unions, neighborhood organizations, peasant groups, and government workers to reliably turn out support. The clientelism and vote buying intrinsic to this system has long ensured the PRI’s dominance in the Estado de México, for example, where it currently controls 68 percent of the municipalities.

But the voto duro is faltering. Meade’s campaign has been disorganized and dysfunctional. But the consistently poor turnout at rallies is less the result of an uninspiring candidate than it is the product of crumbling machinery.

What happened to the machine?

Three long-term processes have contributed to weakening the PRI’s machine. First, government reforms of social policy since the 1990s made it harder for PRI operators to use poverty programs as a tool for ensuring votes.

Second, aggressive anti-corruption efforts emerging from civil society have also targeted vote buying efforts. Citizens now routinely denounce electoral malfeasance on social media, posting pictures of gift cards they receive from candidates, for example.

Third, since the national electoral agency gained its autonomy from the government in 1996, voters have become more willing to trust the integrity of the ballot. This has meant that local PRI bosses cannot always guarantee that their vote buying efforts yield the desired result behind the curtain of the voting booth.

Further, gubernatorial scandals have tarnished the party’s brand, leading to defections and the loss of local control. For instance, in Veracruz, the disgraced PRI governor fled the state in 2016 to avoid prosecution; he was later charged with embezzlement. In the next elections, the party’s coalition went from governing 93 of the state’s municipalities to only 39.

And that’s just one example. In recent election cycles, the PRI lost 38 percent of its municipalities in Chihuahua, 35 percent in Tlaxcala, 31 percent in Hidalgo, and 60 percent in Tamaulipas. To the extent that the PRI’s survival turns on local influence, the collapse of the regional machinery is a crisis.

What comes next?

In the short term, López Obrador’s Morena party will harvest the windfall from the PRI’s collapse, capturing the presidency and a legislative majority on the strength of the anti-PRI vote. Morena could — and likely will — pursue programs that put pressure on what’s left of the PRI. These might include federal social spending strategies that undercut state-level patronage networks and transparency efforts that threaten party elites.

Given that, it’s hard to see how the PRI could revive after this election.

Could Morena become a new PRI?

Many PRI defectors — both low level operatives and high-profile party members — will likely align with López Obrador’s Morena party if it has a big win this year. Local PRI party bosses have already been welcomed into Morena. Some elements of the party’s ideology and approach align with PRI’S principles.

But competition over PRI’S wreckage is likely to be fierce. As parties woo local operators, clientelist groups will suffer internal schisms, further fracturing the remnants of the PRI.

Morena will also face unique challenges. While this is López Obrador’s third run for the presidency, his party is only four years old and its rivals have more experienced operations across the country. At best, Morena will capture five governorships this election, giving it only a tenuous regional presence.

Mexico is likely to see increased political variegation as regional actors build state-level organizations with fewer ties to national party structures. A gubernatorial victory for the small Movimiento Ciudadano party in Jalisco might be a harbinger of that trend. Elections in nine PRI-controlled states are coming up in 2021 and 2022. A dramatic realignment of regional politics is in the offing.

The 2018 election will therefore mark a moment of transition from a relatively stable party system to a fragmented and fluid one. It is not entirely clear whether this will be good or bad for Mexico’s democracy. Competition over clientelist networks could, in the short term, increase incentives for local corruption. Additionally, if party fractiousness leads to legislative stagnation, Mexicans may become more dissatisfied with the political system — in a country where support for democracy is flagging.

The death of the PRI thus ushers in a decidedly uncertain future.

Michael Lettieri is a senior research fellow at the Council on Hemispheric Affairs.