NEW DELHI — Narendra Modi, the most dominating and divisive prime minister India has produced in decades, powered his way Thursday toward this nation’s biggest re-election win in decades.
His brand of brawny Hindu nationalism and pro-business policies seem to have played stunningly well, despite concerns that he had not delivered on promises to create jobs.
With most of the votes counted, Mr. Modi was on track to be the first Indian prime minister to lead his party to majorities in Parliament in back-to-back elections in nearly 50 years.
[Read updates about the overwhelming victory for Mr. Modi and the B.J.P.]
Many Indians see Mr. Modi, 68, as a nationalist icon. He has confronted China, nearly gone to war with Pakistan and brought India closer to the United States. He calls himself India’s chowkidar — watchman — and his success mirrors the rise of right-leaning populist figures around the world.
While he has built a reputation as a crusader who speaks the common people’s language, his detractors say his policies are pulling India’s delicate social fabric apart. His commitment to giving more power to the country’s Hindu majority has struck fear in the Muslim minority and left the country increasingly polarized.
Under him, mob lynchings have shot up, Muslim representation in Parliament has dropped to its lowest level in decades, and right-wing Hindus have felt emboldened to push an extreme agenda, including lionizing the man who shot to death the independence hero Mohandas K. Gandhi.
But in Indian politics today, there is no other figure who can approach Mr. Modi’s aura. His Bharatiya Janata Party, by far India’s richest and most aggressive, has built what critics call a personality cult around him, and in speeches he routinely refers to himself in the third person.
“Are you happy that Modi kills by entering homes?” he thundered at a recent rally, recalling the airstrike he ordered on Pakistan in February. “Doesn’t your chest puff out with pride?”
Political analysts call him “larger than life,” “a cinematic character,” and someone who displays an innate sense for “what people are looking for.”
“Modi has embedded himself in every Indian’s consciousness,” said Arati Jerath, a prominent newspaper columnist.
In contrast, Rahul Gandhi, the leader of the opposition Congress party and the scion of a long political dynasty, is widely perceived, even by some supporters, as cultivating too gentle an image. And though his party cast itself as a unifying force, the results indicated that Congress, once dominant, had suffered a second consecutive disastrous loss.
The election turnout was one for the history books — the largest democratic exercise ever. In seven phases over 39 days, more than 600 million Indians cast ballots at a million polling stations, spread across densely populated megacities and far-flung villages, from high in the Himalayan mountains to tropical islands in the Andaman Sea.
Experts say the force of Mr. Modi’s personality, with many Indians intensely for him or against him, drove turnout to 67 percent, the highest this nation has ever seen.
Even some voters who are worried about the economy or don’t like the way Mr. Modi has stirred up communal divisions say they still see him as the best leader for India now.
“Farmers are in trouble,” said Vinay Tyagi, a wheat and sugar cane farmer in the swing state of Uttar Pradesh. “But we still voted for the B.J.P. because there was no alternative for us. The other candidates weren’t good.”
To keep his job, Mr. Modi campaigned relentlessly, holding 142 rallies and covering 65,000 miles. On the last night before voting ended, he meditated in a Himalayan cave in the same area where he had wandered more than 50 years earlier as a young man searching for purpose.
Mr. Modi will be the first two-time prime minister ever to come from a lower caste. He grew up in a small town north of Ahmedabad, in the state of Gujarat. This has been a powerful part of his narrative; he calls himself a lowly chaiwalla, a tea-seller, a clear jab at India’s elite.
At age 8, he became part of the Rashtriya Swayamsevak Sangh, known as the R.S.S., a right-wing Hindu group that would play a huge role in his life. The R.S.S. is widely seen as a service organization. But its members are the foot soldiers of the Hindu nationalist movement, and some of its critics have accused it of being fascist — in the 1930s the group’s members were inspired by Mussolini’s Italy.
In school, Mr. Modi was known as an average student, but he demonstrated a talent for theater and debating. His forcefulness propelled him up the R.S.S. ranks.
When he was around 18, he took a two-year sojourn and drifted around the Himalayas, contemplating a life as an ascetic priest. In a recent interview, he said that he had bathed in freezing rivers, hung around holy men and learned to “align himself with the rhythm of the universe.”
He also deserted the young woman that his parents had arranged for him to marry when he was a teenager. Even now it is unclear if Mr. Modi ever lived with her.
He didn’t enter politics until much later in life. In his 20s and 30s, he was a preacher for the R.S.S. and then a worker for the B.J.P. Colleagues remember him as passionate, dedicated and efficient.
He oversaw the secret printing of banned pamphlets pushing Hindutva, the belief in the primacy of the Hindu religion and way of life. Analysts say he remains an “ultranationalist” at his core.
“He is very divisive,” said Mrs. Jerath, the newspaper columnist. “He believes in the politics of polarization: us against them, Hindus against Muslims, rich against poor, poor against rich.”
A defining moment came for him in February 2002, when the state of Gujarat exploded in religious riots. Mr. Modi, who was chief minister of the state, was blamed for not stopping the carnage, which included more than 1,000 deaths, most of them Muslim.
From then on, Mr. Modi would be known among the Hindu right as a hero. Many Muslims considered him a killer.
But in the next few years, Mr. Modi deftly switched tack. He became a friend of free enterprise and helped attract thousands of manufacturing jobs to Gujarat.
Business people and middle class voters began to rally around him, seeing him as someone who could get results. At the same time, the dynastic Congress party, which led India for most of its history since independence from Britain, was collapsing, racked by infighting, corruption and the absence of an inspiring leader.
These two story lines converged in 2014, the first time Mr. Modi ran for prime minister.
He emphasized infrastructure, development and rooting out corruption. His B.J.P. won a landslide, and Congress suffered its biggest defeat — winning only 44 seats out of 543, the party’s worst showing in its 100-year-plus history.
Once in office, Mr. Modi moved swiftly to consolidate power, sidelining ministries and making big decisions within a very small circle of advisers. He quickly announced a series of high-profile, symbolic programs.
One was building 100 million new toilets, a goal his government has nearly reached and something that no other Indian prime minister had ever tackled as assiduously. Many voters in this election cited Mr. Modi’s toilet campaign, and its benefit for privacy, safety and sanitation, as one of the reasons they gave him their vote.
But there were also troubling signs. Hindu nationalists, encouraged by the election of one of their own to the country’s highest office, began harassing Muslims and low-caste Hindus. Sectarian violence and deaths increased.
Mr. Modi began appointing Hindu nationalists to key posts at universities, ministries and eventually, nonpartisan bodies like the central bank. Government agencies began to change place names from Muslim to Hindu and rewrite children’s history books, lopping out entire sections on Muslim rulers.
The honeymoon period ended in November 2016, when Mr. Modi suddenly invalidated most of the nation’s currency. The so-called demonetization, carried out in the name of fighting corruption, made it nearly impossible to use cash in a country that relied on it for buying everything from vegetables to a home.
Seven months later, the government replaced a complex set of state taxes with a single national goods and services tax. While most economists say the move was a sensible long-term reform, the new system was so complicated that it caused chaos at millions of small and mid-sized businesses.
The twin blows battered the economy and brought job growth to a standstill in a country where 5 million young people enter the work force every year. In the quarter that ended in December, the country’s economy grew 6.6 percent — enviable for many countries, but the slowest rate in five years.
Among the most disappointed with Mr. Modi’s economic promises were India’s farmers. Half of India relies on agriculture and protests erupted around the country, with some farmers dumping nearly worthless milk into the streets.
Still, Mr. Modi continued to cut red tape for businesses, invest in major infrastructure like roads and tackle some of India’s biggest problems. His most ambitious welfare program, a new attempt at universal health care for the poor, was nicknamed Modicare.
As the campaign began, many predicted that the country’s economic challenges would make it difficult for Mr. Modi and the B.J.P. to keep control of Parliament.
But everything changed on Feb. 14, when a suicide bomber blew up a bus of paramilitary forces in Pulwama in the state of Kashmir, which both India and Pakistan claim as their own. Jingoism surged, and so did Mr. Modi’s approval ratings. He campaigned hard on national security, and voters seemed to respond to that and his tilt back toward Hindu nationalism.
“The scale of the win is remarkable,’’ said Menaka Guruswamy, a senior lawyer in India’s Supreme Court and lecturer at Columbia Law School. But she added:
“I don’t know of a word that begins to capture how deeply divided we are at this point.’’