Abelardo de la Espriella, the Trump-endorsed criminal-defense lawyer who has never held public office, claimed victory in Colombia's presidential runoff Sunday with 49.7 percent of the vote to leftist Senator Ivan Cepeda's 48.7 percent, electoral authorities reported with 99.9 percent of ballots counted. Cepeda declined to concede and said his campaign is challenging the results from 33,000 of the country's 122,000 ballot boxes.

The margin, roughly 247,000 ballots out of more than 26 million cast, swings Colombia sharply to the right and hands President Trump a regional ally a week after his administration finalized a Geneva memorandum with Iran. It also sets up an immediate institutional test: no Colombian recount has ever overturned a presidential result, according to The Associated Press, and the first-count margin of error usually runs in the low thousands.

The challenge

Cepeda, a 63-year-old senator and the chosen successor of outgoing leftist President Gustavo Petro, told supporters at a Bogota rally that he would wait for a ballot-by-ballot review before acknowledging the official tally. "Once the count has been completed and its final result is known, and the corresponding checks have been carried out, we will acknowledge the official result," he said, according to CBS News.

He paired the legal challenge with an offer of dialogue. "We are open to dialogue; we are willing to reach agreements as long as they are respectful, genuine, and reflected in political actions that benefit the nation and preserve the historical progress we have already achieved," Cepeda said, Al Jazeera reported.

De la Espriella addressed his own supporters from behind bulletproof glass in the Caribbean city of Barranquilla. "I will govern for all Colombians," he said. He also issued a warning to his rival, telling Cepeda to respect the vote and not to "even think about stoking violence."

Protests and celebrations

As the count firmed up Sunday night, thousands of protesters gathered in Colombia's largest cities. In Cali, demonstrators burned American flags and clashed with riot police who used teargas to disperse crowds, CBS News reported. In Bogota, protesters burned tires and threw bricks at officers.

"We've already had many years of right-wing governments that care only about making the rich richer," a 26-year-old student identified as Natalia told Agence France-Presse in remarks carried by CBS News.

Elsewhere, De la Espriella's backers poured into the streets in the canary-yellow national football jersey he had adopted as a campaign uniform. Major business guilds congratulated him, and upper- and middle-class districts of Bogota and Medellin celebrated, according to Al Jazeera.

Washington's hand

Trump called De la Espriella to congratulate him and posted that "He Won, BIG!" Secretary of State Marco Rubio said Washington "looks forward to working closely with your incoming administration." De la Espriella holds U.S. and Italian citizenship in addition to Colombian and maintains homes in several countries.

During the campaign he told AFP he would scrap peace talks with dissident armed groups and launch a 90-day campaign of U.S.-backed airstrikes against them, a posture that would unwind the framework built on the 2016 accord with the Revolutionary Armed Forces of Colombia. Cartels and FARC dissident factions still control pockets of the country, cocaine exports are at record highs and inequality remains among the world's worst.

Colombia is the seventh Latin American country in the current cycle to elect a right-wing leader, joining Argentina, Bolivia, Chile, Ecuador, Honduras and Peru, Semafor noted, citing Harvard political scientist Steven Levitsky's description of the moment as an unusual alignment for Trump.

The caveats

The sources reporting today's result lean center to lean-left; right-leaning outlets had not pushed back publicly on the protest coverage by press time. The closeness of the result is itself a constraint on De la Espriella's program: with a divided Congress, he is likely to have to soften pieces of his platform to assemble majorities, Al Jazeera reported, and an investigation by the local outlet La Silla Vacia found that many of the businesses he cites as his record have been dissolved or are carrying losses.