Varanasi, India

On a blazing summer day, 20-year-old Rambali Sonkar plies passersby with fresh mango juice along a highway two hours outside this Hindu holy city. Each time a car stops, Mr. Sonkar steps out from the shade of his canopied cart and into the road-melting 108-degree heat. A small plastic glass of juice costs 10 rupees (14 cents) in this impoverished corner of Uttar Pradesh, one of India’s poorest states.

Prime Minister Narendra Modi represents Varanasi in the Lok Sabha, the lower chamber of India’s Parliament. Like many Indians, Mr. Sonkar hopes Mr. Modi and his Bharatiya Janata Party win a second five-year term when the votes are counted on May 23. He credits the prime minister with building roads, providing the poor with toilets and cooking-gas cylinders, and cracking down on corruption.

Mr. Sonkar identifies with Mr. Modi’s humble roots as a former tea-seller from an underprivileged caste. He also believes that Mr. Modi has “made India’s name shine in the world.”

Many people across this nation of 1.3 billion people appear to share the juice vendor’s estimation of how the world views Mr. Modi. These Indians see him as a towering figure who rubs shoulders with the planet’s most powerful leaders as a peer. Compared with his predecessor, the soft-spoken Oxford-trained economist Manmohan Singh, Mr. Modi comes across to his fans as the embodiment of a new India—muscular, assertive and aggressively self-confident.