On April 1, 2017, Irshad Khan, a slight twenty-six-year-old with glossy black hair and the faint shadow of a beard and mustache, helped his eighteen-year-old brother, Arif, and their father, Pehlu, load two cows into the bed of their white Mahindra pickup truck. The Khans were heading from a cattle market in Jaipur, the capital of Rajasthan, to their village of Jaishingpur, a four-hour drive away. Muslims and lower-caste Hindus, or Dalits, live side by side in the village, harvesting mustard from fields of yellow flowers. The village, home to six hundred people, is relatively well-off, and has grown more prosperous, as Delhi has mushroomed into a megacity of twenty-seven million and the price of land surrounding the city has skyrocketed. Some Muslim families in the village, including the Khans, are wealthy traders who transport goods like sand and vegetables to the cities around Delhi.

That afternoon, Irshad climbed into the truck alongside his father and brother. Cows are sacred to Hindus but Irshad had made this trip dozens of times since he was a boy. He’d heard rumors of potential trouble for Muslims at roadside checkpoints, where members of a militant Hindu youth group called the Bajrang Dal were intimidating Muslim traders in the name of protecting cows. Still, Irshad wasn’t nervous. “We had no fear at all,” he told me recently. “We were coming from a government-organized fair, and buying and selling cows is a legal business.”

The militant Hindu nationalism that the group espouses is not new. Nathuram Godse, who assassinated Gandhi, on January 30, 1948, was a member of the Rashtriya Swayamsevak Sangh, or R.S.S., a violent right-wing organization that promotes Hindu supremacy. Members of the Bajrang Dal are the movement’s foot soldiers, deployed in instances of mob violence or for targeted attacks against Muslims and other religious minorities. Founded in 1984, the group was part of a movement to destroy the Babri Masjid, a sixteenth-century mosque located in Ayodhya, India, which was built by the emperor Babur. (The mosque was ultimately demolished during a violent R.S.S. rally in 1992.) Since its early days, the group has formed some twenty-five-hundred cells across the country. I first reported on these cells, called akhadas, in 2005, in Dharavi, Mumbai, Asia’s largest slum, where, in the name of protecting cows, the militants recruited impoverished Hindu boys to their violent cause. Paul Richard Brass, a professor emeritus of political science at the University of Washington, has called the Bajrang Dal “a somewhat pathetic but nevertheless dangerous version of the Nazi S.A.”—or the Brownshirts, the Nazi Party’s first paramilitary organization.

For much for the past thirty years, the Bajrang Dal has either been banned or has lurked at the margins of Indian society. But in 2014 Narendra Modi, the leader of the Bharatiya Janata Party, or the B.J.P., a right-wing political party that was an offshoot of the R.S.S., was elected Prime Minister. Since then, the militant group has been legitimized and grown exponentially more powerful. In the past seven years, according to Factchecker.in, an organization that tracks hate crimes, there have been a hundred and sixty-eight attacks by Hindu extremists, in the name of protecting cows, against Muslims and other religious minorities. The attacks left forty-six people dead. “It’s really a very, very bad moment for Muslims in India,” Salman Khurshid, India’s former foreign minister and the author of a forthcoming book, “Invisible Citizens,” on the systematic oppression of Muslims in the country, told me. He laid out several setbacks for Muslims in Indian history. “First, in 1857, the failure of the war of independence,” he said, citing the brutal British repression of a popular uprising, in which Muslim and Hindu soldiers rose up together against the colonialists. Then partition, when British India divided into two independent states, predominantly Hindu India and predominantly Muslim Pakistan, and more than a million people died in sectarian violence. Khurshid cited the destruction of Babri Mosque as a third example. And then told me, “the next big setback is the rise of this government.” Under Modi, incidents of communal violence rose twenty-eight per cent between 2014 and 2017.

When Irshad and his family got stuck in traffic in Alwar, about halfway home from the cow market, a gang of eight men surrounded the Khans’ truck and demanded to know what was in the back. “Cows,” Pehlu said, and handed one of the men the official papers to prove that the cows were legal. “We’re Bajrang Dal, and we don’t care about these papers,” the man replied, tearing them up and throwing them on the road. Then the men pulled the Khans from the truck and passed them around, angrily asking questions. The Khans had driven by a police station about half a mile back, and they were still almost within sight of it. Irshad thought that if they could just hang on for a few minutes and keep the militants talking, the police would arrive to help them. But the minutes passed, and the police didn’t come. Instead, dozens more men pressed in around them and began beating them; Irshad felt a stinging cuff to his ear, and then the blows became heavier and more regular, drawing blood. Arif fell to the ground and curled into the fetal position. Pehlu, who was dressed in all white and had a small beard, a sign of religious devotion, was beaten unconscious.

Eventually, the police broke up the crowd and carried the Khans to a local hospital. An angry mob of villagers followed and surrounded the building. A kindly doctor locked Irshad and his brother in a room for their protection, and the boys recalled listening to the sound of feet as the villagers clambered onto the hospital’s roof. “We could hear them shouting they wanted to kill all three of us,” Irshad told me. Over the next two days the boys began to recover, but, on April 3rd, Pehlu died of his injuries. When the news of his death spread, the boys said that the mob returned and demanded his body so that they could desecrate it. The doctor hid the corpse in the hospital basement, and a police unit moved the boys to another hospital for their safety. When the brothers were in stable enough condition to go back to Jaishingpur, hundreds of people arrived from their village and neighboring ones to escort them home.

This spring, Modi is up for reëlection, and campaign season in India has sometimes sparked violence between Hindu nationalists and Muslims in the past. The B.J.P. is especially anxious this year, because of a series of unexpected losses in recent state elections. In Rajasthan, India’s first Minister of Cows, who presided over a sanctuary for the animals, was soundly defeated. These electoral losses have little to do with a backlash against right-wing Hindu nationalism. Instead, they reveal growing dissatisfaction with the failure of Modi and the B.J.P. to deliver on the economic development that they promised five years ago. In 2014, most Indians voted for Modi in the hopes that he would lift their economic status. In fact, India’s economy is the fastest growing in the world, and more than two-hundred and seventy-million people have risen out of poverty over the last fifteen years. Yet, under Modi, growth is lower than promised and India is facing its highest rate of unemployment in forty-five years. Over the past several weeks, Modi has announced a new round of economic measures designed to placate frustrated voters, including delivering cash handouts to struggling farmers.