MANAGUA, Nicaragua — The nights were the hardest.
From the moment Medardo Mairena decided to run for president, in direct challenge to Nicaragua’s authoritarian leader, he was certain the security apparatus would eventually come for him.
Over the summer, he watched as other opposition leaders disappeared. One by one, they were dragged from their homes amid a nationwide crackdown on dissent by the president, Daniel Ortega, whose quest to secure a fourth term had plunged the Central American nation into a state of pervasive fear.
Since June, the police have jailed or put under house arrest seven candidates for November’s presidential election and dozens of political activists and civil society leaders, leaving Mr. Ortega running on a ballot devoid of any credible challenger and turning Nicaragua into a police state.
Mr. Mairena himself was banned from leaving Managua. Police patrols outside his house had scared away nearly all visitors, even his family.
During the day, Mr. Mairena kept busy, campaigning over Zoom and scanning official radio announcements for clues to the growing repression. But at night he lay awake, listening for sirens, certain that sooner or later the police would come and he would disappear into a prison cell.
“The first thing I ask myself in the morning is, when are they coming for me?” Mr. Mairena, a farmers’ rights activist, said in a telephone interview in late June. “It’s a life in constant dread.”
His turn came just days after the call. Heavily armed officers raided his home and took him away late on July 5.
He had not been heard from until last Wednesday, when relatives were allowed one brief visit. They said they found him emaciated and sick, completely disconnected from the outside world.
Government critics say the unpredictability and speed of the wave of arrests have turned Nicaragua into a more repressive state than it was during the early years of the dictatorship of Anastasio Somoza, who was overthrown in 1979 by the Sandinista Revolutionary Movement led by Mr. Ortega and several other commanders. The Sandinistas governed the country until losing democratic elections and ceding power in 1990. In 2007, Mr. Ortega returned as president.
After 14 years in power, unpopular and increasingly isolated from Nicaraguan society in his gated compound, Mr. Ortega appears intent on avoiding any real electoral competition. The five presidential candidates still on the ballot with him are little-known politicians with a history of collaboration with the government. Few in Nicaragua consider them genuine challenges to Mr. Ortega.
The crackdown, which has extended to critics from any social realm, has spared no political dissidents, no matter their personal circumstances or historical ties to Mr. Ortega.
The victims of persecution have included a millionaire banker and a Marxist guerrilla, a decorated general and a little-known provincial activist, student leaders and septuagenarian intellectuals. No government detractors feel safe from the sudden night raids, whose only certainty has been their constancy, more than 30 Nicaraguans affected by the crackdown said in interviews.
“Everyone is on the list,” said one Nicaraguan businessman, whose family home was raided by the police and who spoke on condition of anonymity for fear of reprisal. “You’re just trying to figure out how high or low your name is on it, based on the latest arrest.”
The wave of repression and fears of political violence have pushed thousands of Nicaraguans to flee the country in recent months, threatening to worsen a mass migration crisis at a time when the Biden administration is already struggling with record numbers of immigrants trying to cross the southern border.
The number of Nicaraguans encountered by U.S. border guards has exploded since the crackdown, with a total of almost 21,000 crossing in June and July, compared with fewer than 300 in the same months last year, according to the Department of Homeland Security. About 10,000 more Nicaraguans have crossed south into neighboring Costa Rica in the same months, according to the country’s migration agency.
The exodus has included the rich as well as the poor and is driven as much by fears of escalating violence as by concerns over a looming economic crisis in a country heading steadily toward international isolation.
Dozens of prominent Nicaraguan businessmen have quietly left for Miami in recent months, halting their investments in the country, according to interviews with several entrepreneurs who did not want to be quoted for fear of reprisals. And most international development banks, whose loans have propped up the Nicaraguan economy in recent years, are expected to stop disbursing new funds following the elections, which the United States has said it is unlikely to recognize in their current form.
Some Nicaraguans have left out of fear of a return of the street violence that traumatized the country in 2018, when pro-government paramilitaries and police forces broke up opposition protests, killing more than 300.
“I’m scared that another massacre is coming,” said Jeaneth Herrera, who sells traditional cornbread on the streets of Managua. Her sales have fallen sharply in recent months, she said, as political uncertainty has pushed up food prices. “I don’t see a future here.”
The detained men and women, some of them top former Sandinistas, have been charged with crimes ranging from conspiracy to money laundering and murder, accusations their families and associates say are trumped up. Most spent weeks, or months, in jail before any communication with relatives or lawyers.
Several of those arrested are in their 70s and have health problems. They were put in the same jail as other prisoners, relatives said, and denied access to independent doctors or to medicines delivered by relatives.
A retired Sandinista general, Hugo Torres, was arrested despite having staged a raid that helped Mr. Ortega break out of Mr. Somoza’s jail in the 1970s, potentially saving his life. The former Sandinista minister Víctor Hugo Tinoco was detained and his house ransacked for hours by the police in front of his daughter, Cristian Tinoco, who has terminal cancer.
The police also smashed into the presidential candidate Miguel Mora’s home at night and dragged him out in the presence of his son Miguel, who has cerebral palsy, said Mr. Mora’s wife, Verónica Chávez.
“He kept repeating that night, ‘Where is Papa?’” Ms. Chávez said. “It felt like living in a horror movie.”
The cases against the political prisoners are being heard in closed courts without the presence of legal counsel. This has left their relatives and the public in the dark about the evidence presented, adding to the climate of fear.
Those who tried documenting the legal process — relatives, lawyers, journalists — say they were threatened or faced with similar accusations, and in some cases forced to flee the country or go into hiding. A lawyer for one of the jailed candidates was himself arrested late last month for being a member of an opposition party.
“Absolutely no one has any idea what they are accused of, or what’s in their cases,” said Boanerges Fornos, a Nicaraguan lawyer who represented some of the detained politicians before fleeing the country in June. “There’s a systematic destruction of all nonofficial sources of information. The regime likes to operate in the dark.”
After dismantling opposition parties and jailing their candidates, the government shifted its attacks to others with independent views: the clergy, journalists, lawyers, even doctors. In the past few weeks, the government has called Nicaragua’s Catholic bishops “children of demons,” threatened the medics who raised alarm about a new Covid-19 wave and taken over the installations of the country’s biggest newspaper, La Prensa.
The uncertainty behind the seemingly arbitrary arrests has made the situation harder to bear for the victims’ families.
“They have their chess board already set up, and you’re just a pawn on it,” said Uriel Quintanilla, a Nicaraguan musician whose brother Alex Hernández, an opposition activist, was recently detained.
Since then, Mr. Quintanilla said, he has not heard news of his brother or the charges against him.
“The check and mate against you have already been planned out,” he said. “We merely don’t know at what moment it will come.”
Alex Villegas contributed reporting from San José, Costa Rica.