LA PAZ, Bolivia — Exit polls issued early Monday showed Bolivia's socialists taking a seemingly insurmountable lead in the country's bitterly fought presidential election, a result that, if confirmed by the official tally, would amount to a massive popular rebuke of the right-wing forces that drove the left from power a year ago.

Sunday’s much-delayed election was a do-over of last year’s contest. That vote ended with longtime socialist President Evo Morales fleeing into exile as opponents alleged electoral fraud and supporters decried a “coup.”

Morales, banned from running this time, watched from Argentina as his former finance minister, front-runner Luis Arce, 57, faced two main competitors who sought to stop a socialist comeback: centrist former president Carlos Mesa, 67, and right-wing nationalist Luis Camacho, 41.

The exit poll by the firm Ciesmori, with margin of error of less than 2 percentage points, indicated that Arce, the candidate of the Movement Toward Socialism (MAS) party, had claimed 52.4 percent of the vote, compared to Mesa’s 31.5 percent and Camacho’s 14.1 percent. A second exit poll by a group of universities and Catholic institutions showed similar figures, giving Arce 53 percent and Mesa 30.8 percent.

In a tweet, the right-wing, U.S.-backed interim president, Jeanine Áñez Chavez, noted that the official tally was still being counted. But she nevertheless recognized Arce’s apparent victory.

“We do not yet have an official count, but from the data we have, Mr. Arce and [his vice-presidential candidate] Mr. [David] Choquehuanca have won the election. I congratulate the winners and ask them to govern with Bolivia and democracy in mind.”

 If the exit poll numbers are confirmed by the official count, which was being tabulated slowly late Sunday, it would be more than enough to avoid a November runoff and claim outright victory.

“We have recovered democracy,” Arce said in a public speech early Monday. “We promise to respond to our pledge to work and bring our program to fruition. We are going to govern for all Bolivians and construct a government of national unity.”

Experts cautioned that the exit polls are not the same as the official count, of which less than 5 percent was tallied by midnight. But they offered what many observers called a fairly precise snapshot of a huge wave of support for the socialists, who had ruled the country since 2006 before being forced out last year following claims of fraud.

One of Arce’s successful tactics appeared to be a major distancing of his candidacy from Morales. But the polarizing former president nevertheless seemed to portray the election as a vindication.

“Bolivia is an example to the world,” Morales told reporters in Buenos Aires. “Very soon our country will begin a new stage of great challenges. We must put aside differences and sectoral and regional interests to achieve a great national agreement.”

In a surprise decision Saturday, Bolivia’s electoral tribunal announced it would not release the traditional quick-count projection of the outcome as initially expected Sunday. The tribunal said it would instead wait to release results until all ballots were counted or tallies showed an indisputable trend, something that could take at least a day or two, and potentially up to a week.

Late Sunday, Salvador Romero, head of the electoral council, would not confirm a timeline for releasing the definitive results.

“This process, at this stage, can be slower and accelerate progressively,” he told reporters in La Paz. “We ask the people for patience. We need to be certain about the results.”

An outright win for the socialists would amount to a major reversal of fortune for the powers that be in this impoverished Andean nation and mark a major victory for the Latin American left. It would also mark a stunning defeat for the right, which sought to sell its actions to purge the socialists in Bolivia as a “liberation” of the country — a liberation its people seemed not to want.

Áñez, a right-wing firebrand who took over after Morales’s exile, dropped out of the race due to low poll numbers. She has been blamed for haphazard handling of the coronavirus pandemic, as well as presiding over a wave of repression against leftists during her year in power. Observers say officials in her government as well as senior members of the military brass could potentially face charges from a new socialist government — although Arce told The Washington Post in an interview last week that he would not seek to influence the justice system.

 “It’s an end to the politics of persecution and an opening for thorough, credible investigations of human rights violations, corruption and other irregularities,” said Kathryn Ledebur, director of the Andean Information Network. “Justice for these issues is the first crucial step toward reconciliation.”

Going into Sunday, opinion polls showed Arce close to the threshold needed for a first-round victory. To avoid a runoff, a candidate had to win more than 50 percent of the vote, or at least 40 percent with a 10-point margin of victory.

Analysts say Mesa, running second in the polls, would become the favorite in a second round of voting next month, assuming the opposition to the socialists coalesced around him. Camacho trailed both men in the polls by significant margins.

Carla Nina Martínez, a 30-year-old nurse voting in a rural area just south of La Paz, described herself as a longtime supporter of the left. But she said she was changing her vote this year to support Mesa.

“I value some things that President Evo Morales did. Everything was going very well,” she said. “But in the end, as always, politics end up being corrupt.”

 A survivor of covid-19, the disease caused by the novel coronavirus, she said she blamed the Áñez government for a poorly executed coronavirus plan.

“During the high points of the pandemic, we were never provided with personal protective equipment, and health personnel ended up being infected,” she said.

Santos Vallejo, 52, said the country’s bad economy in the midst of the coronavirus pandemic led him to vote for the socialists.

During Morales’s three terms, the socialists were credited with a successful drive to turn Bolivia into a leader in the effort to fight poverty in Latin America. At the same time, they embraced a “Socialist lite” approach that maintained relatively business-friendly policies — especially as compared to the more far more repressive and severe socialist government in Venezuela.

Under socialist governments, “we had jobs,” Vallejo said outside a polling station in El Alto, a socialist stronghold near La Paz. “I believe MAS will win because we, the poor, are with them.”

More than 10,000 troops were called to keep the peace. In a message clearly aimed at the socialists, Áñez’s influential interior minister, Arturo Murillo, led a show of force Saturday with soldiers and armored vehicles on the streets of La Paz. Murillo said the effort was meant to prevent “the return of dictators” — a clear reference to Morales, who was democratically elected three times before his controversial bid for a fourth term last year.

Arce has sought to distance himself from Morales. In an interview last week with The Post, Arce said Morales would need to face the justice system to defend himself against “numerous” charges if he returned.

“We think that our comrade Evo has every right, if he so wishes, to return to the country and defend himself,” Arce said.

Faiola reported from Miami. Ana Vanessa Herrero in Caracas, Venezuela, contributed to this report.