The Dominican Republic is deporting tens of thousands of Haitians this year, despite pleas from the United Nations to stop as they flee gang-fueled lawlessness. The Dominican president, Luis Abinader, is going even further, building a border wall between the two countries that share the Caribbean island of Hispaniola.

As Dominican voters head to the polls on Sunday in a general election, the immigration crackdown, along with an anticorruption drive and growth in tourism, has made Mr. Abinader, who is seeking a second term, the clear front-runner.

The election showcases how the Dominican Republic, with one of Latin America’s best-performing economies, stands apart from other countries in the region, where many leaders who rose to power in the same period as Mr. Abinader are dogged by dismal approval ratings.

Mr. Abinader’s use of contentious restrictions on Haitian migrants also underscores an iron-fisted approach to migration that makes the Dominican Republic something of an outlier in the region.

“This is definitely not a ‘change’ election as many others have recently been in Latin America,” said Michael Shifter, a senior fellow at the Inter-American Dialogue, a Washington-based research organization.

Credible polls indicate that a solid majority of Dominicans approve of the tenure of Mr. Abinader, 56, a market-friendly former executive in the tourism industry.

He has dominated the race over various rivals including his closest competitor, Leonel Fernández, a three-time former president, and is within striking distance of a first-round win on Sunday.

A runoff will be held if no candidate gets more than 50 percent of the vote. Many in the large Dominican diaspora are allowed to cast ballots in the election, with more than 600,000 eligible voters in the United States and more than 100,000 in Spain.

Much of Mr. Abinader’s support is owed to his anti-graft initiatives. He won his first term in 2020 by vowing to clean up the corruption that has long been embedded in the political culture of the Dominican Republic, a country of 11.2 million people.

He appointed Miriam Germán, a former Supreme Court judge, as attorney general. She has overseen investigations that have ensnared high-ranking officials in the previous administration, including a former attorney general and a former finance minister.

The investigations have largely focused on people opposed to Mr. Abinader, prompting criticism that his own government has been spared. But other moves, like the passage in 2022 of an asset forfeiture law, offer hope of lasting change. The forfeiture law is viewed as an important and pioneering tool to disrupt and dismantle criminal enterprises, depriving them of property acquired through illicit activities.

Rosario Espinal, a Dominican political analyst, said Mr. Abinader could have won re-election simply by focusing on the battle against corruption, as he did in 2020, “but not with the margins that he wants.”

Instead, Ms. Espinal said, Mr. Abinader embraced the nativist immigration policies traditionally pushed by the Dominican far right. “He needed to find a new topic that would resonate,” she said. “He found that in migration.”

Exploiting anti-Haitian sentiment is nothing new in the Dominican Republic.

Rafael Trujillo, the xenophobic dictator who ruled the country from 1930 to 1961, institutionalized a campaign portraying Haitians as racially inferior and, in 1937, ordered the massacre of thousands of Haitians and Dominicans of Haitian descent.

Nearly every other country in the Americas offers birthright citizenship. But a 2010 constitutional amendment and a 2013 court ruling excluded Dominican-born children of undocumented migrants from citizenship.

In practical terms, that means that roughly 130,000 descendants of Haitian migrants are living in the Dominican Republic without citizenship despite being born there, according to rights groups.

As Haiti descended into chaos following the assassination in 2021 of the Haitian president, Jovenel Moïse, Mr. Abinader built on the anti-immigrant measures already enshrined in Dominican law.

He suspended visas for Haitians in 2023, and then closed the border with Haiti for nearly a month, dealing an economic blow to his neighbor in a dispute over the construction of a canal in Haiti using water from a river shared between the two countries.

“He has shown who wears the pants on this issue,” said Robert Luna, who works in marketing, about Mr. Abinader’s migration policies. “He’s fighting for what the fathers of the nation wanted.”

Dominican immigration officials have gone considerably further, with some accused of looting the homes of Haitians and embarking on a campaign to detain and deport Haitian women who were pregnant or who had just given birth.

Pablo Mella, academic director of the Instituto Superior Pedro Francisco Bonó, a Dominican university, called Mr. Abinader’s policies toward Haiti a “public and international disgrace,” particularly the treatment of pregnant Haitian women.

“What happens is that’s what gets votes,” Mr. Mella added. “Candidates are vying to see who’s the most anti-Haitian of all.”

A large majority of Dominican voters say that the upheaval in Haiti is influencing how they will vote. And Mr. Abinader is clearly benefiting from such concerns, with nearly 90 percent of voters expressing support for his construction of a border wall.

Mr. Abinader has defended his migration policies, saying they are no different from what countries like Jamaica, Bahamas, the United States and Canada have done to limit the arrival of Haitians fleeing the crisis.

“I have to do whatever is necessary to secure our people,” Mr. Abinader told the BBC in a recent interview. “We are just applying our law.”

Mr. Abinader’s office did not immediately respond to a request for comment.

Still, some voters are not sold on the incumbent. Tirso Lorenzo Piña, a doorman and an evangelical Christian, said he was unhappy with Mr. Abinader’s support in the United Nations for admitting Palestine as a member.

“Everyone has their own ideology, concepts, ways of thinking,” Mr. Piña said. “But I don’t like him.”

Still, Mr. Abinader is benefiting from a divided opposition and broad consensus in the Dominican Republic in favor of investor-friendly policies that have spurred economic growth. His handling of the pandemic also helped, distributing vaccines relatively quickly and allowing the Dominican tourism industry to bounce back while other countries were requiring visitors to go into quarantine.

Tourism is a pillar of the economy, accounting for about 16 percent of gross domestic product. The World Bank expects the Dominican Republic’s economy to grow by 5.1 percent this year.

While the Dominican Republic’s economy has expanded over the last two decades at a rate three times the average in Latin America, enduring inequality has opened Mr. Abinader to criticism. He has responded by expanding popular cash-transfer programs for the country’s poorest residents.