SAN JOSE (Reuters) - The resounding victory of a pro-gay marriage candidate in Costa Rica’s presidential run-off vote on Sunday staved off a resurgent Christian evangelical movement that proved unable to translate strong social conservatism into a win.

Costa Rica's president-elect Carlos Alvarado Quesada greets the media outside his house in San Jose, Costa Rica April 2, 2018. REUTERS/Jose Cabezas

Gay rights have expanded across Latin America in recent years, especially in South America, though many advocates feared there could be a backlash from practicing Christians energized by growing evangelical Protestantism.

The election campaign was dominated by opposition candidate and evangelical Fabricio Alvarado Munoz’s forthright criticism of gay marriage. Weeks of polling had suggested the election was either too close to call, or leaning in his favor.

In the end, the center-left candidate of the ruling party, Carlos Alvarado Quesada, triumphed by a 20-point margin.

But voters and analysts said the result did not mean Christian conservatism was dead in Costa Rica.

Alvarado Munoz won nearly 40 percent of the vote, but his failure owed much to his aggressive approach in what is arguably Central America’s most laidback nation, they said.

“There’s no question that Fabricio’s extremism created fears and doubts among people,” said Alejandro Abarca, an economics professor at the University of Costa Rica.

And his passionate opposition of gay marriage could not make up for holes in economic aspects of his platform, he added.

“Fabricio was horrible in the debates. He came across as unprepared,” Abarca said.

A pentecostal singer and former TV anchor, Alvarado Munoz won the first round of voting in February after pledging to ignore a ruling by the San Jose-based Inter-American Court of Human Rights that Costa Rica should adopt gay marriage, even threatening to quit the court.

Doing so, he tapped into a growing trend towards conservative evangelical Christianity in Costa Rica, where 40 percent of Protestants say they were brought up as Roman Catholics, a 2014 Pew Research Center study shows.

Among people aged 18 to 34, Protestants were significantly more likely to be religious than Catholics in Latin America, including Costa Rica, the study showed.

All told, barely 30 percent of Costa Ricans favor same-sex marriage, according to a survey released in January by the CIEP think tank of the University of Costa Rica.

Fired by that religious zeal, evangelical pastors and churches have mounted strong opposition to gay marriage, seeking to characterize such liberalism as “gender ideology.”

Alvarado Munoz’s campaign used the term to attack what it saw as a movement led by gays and feminists trying to destroy the traditional family. In the end, his evangelical National Restoration Party won 14 seats in the 57-member Congress.

In the previous election it had secured just one.

Still, mixing religion with politics has its limits, said 28-year-old musician Oscar Jimenez, who felt Munoz’s manifesto promise to follow “the Christian ethic,” with no mention of other faiths, went too far for moderate voters like him.

“This had never happened before, such polarization around this issue,” Jimenez said.

Nevertheless, with problems such as poverty still widespread in Costa Rica, experts said the Church would continue to play a significant role in politics.

“Societies get more polarized when religious issues arise. The polarization we saw in the final stages of the campaign is bigger than in the past,” former Costa Rican President Oscar Arias told reporters before casting his vote on Sunday.

“We need to figure out how to heal the wounds and if the social fabric has unraveled somewhat, we need to do everything possible to fix it,” the Nobel peace laureate added.