I’m trying to get to Sabarimala Temple, one of India’s holiest Hindu shrines. “You’re going to Sabarimala?” “We’re going to the top.” But it’s not easy. “We go talk to him?” “That man.” “O.K. Let’s go.” There are police everywhere. “Hello, sir.” They seem to be on high alert. “Times?” “New York Times.” “American. American.” “’New York Times. The New York Times, over.” “Thanks for your help, yeah?” “Thank you, sir.” In the end, I get through, and I walk among thousands of pilgrims who are here to worship the god Ayyappa. “Oh, cool. There it is. There it is. This is it. It’s like a whole little town here.” One group I don’t see? Women, between the ages of 10 and 50. The devout believe Ayyappa is a celibate god and those women could tempt him. But I do meet the vigilantes who are here to stop any young women from entering. “Right here, what are you looking for?” “Right here, we’ll be asking: How old are you?” Traditionally, women of childbearing age have been banned from coming here. But last year, the Indian Supreme Court said it was illegal to block them. The decision erupted into a religious crisis that lasted for months. [chanting] The devout were furious. They said it was an assault on their religion. And the political right wing seized an opportunity. They rushed in, calling themselves the defenders of tradition, and helped fuel violent protests. So, I came here to feel the reverberations. How much can a controversy over one temple shape politics in the world’s largest democracy? I’m Jeffrey Gettleman. It’s election time, and Prime Minister Narendra Modi will likely win another five-year term. [cheering and applause] This is the first time I’ve actually seen Modi in person. And wow, to rouse his base, he knows exactly what to say and how to say it. He’s trying to leverage the controversy over Sabarimala Temple into votes for his party, the B.J.P. Reporter: “Hello, ma’am. So, you like Modi?” “Yeah, definitely.” “Why?” “I think —” Reporter: “Some people say B.J.P. divides India between Hindus and Muslims. What do you say?” Reporter: “Even the Muslims?” “Yeah.” Reporter: “So, you think of it as Hindus or Indians?” Among many Modi supporters, this is a core belief, that India is a Hindu nation, despite the fact that people of many religions live here. And I wonder what this means for minorities, and for the future of this democracy. See, since Modi came to power five years ago, hate crimes against Muslims have shot up. Lynch mobs have killed dozens of people suspected of slaughtering cows, which are sacred to Hindus. To be clear, Modi doesn’t encourage the violence, but critics say he hasn’t forcefully condemned it, either. Now, his party is riding this wave of Hindu nationalism into the most secular parts of the country. That’s another reason why I came here, to Kerala. It’s a progressive state. Modi’s party has never won a single Parliament seat from here. This is the party that hold the most seats in Kerala, the Indian National Congress. It stands for a pluralist, secular India. So this is the last place I’d expect the Hindu right to succeed. But the state has turned into a real battleground, all because of Sabarimala. Not far from the temple, I meet up with K. Surendran on the campaign trail. He’s a B.J.P. candidate for Parliament, and he was one of the thousands arrested for rioting at Sabarimala and physically blocking women from entering. It made him a hero of the Hindu right. It’s impressive to see him work the crowd. He doesn’t even have to say much. [singing] People here know exactly where he stands on Sabarimala, and that’s what matters. Modi’s party has another advantage — a strong ground game. These men are volunteers with the R.S.S. — The hardline Hindu organization known for churning out leaders. They’re basically Modi’s foot soldiers. There are thousands of branches like this one. Modi, himself, actually rose up through their ranks. Hari Mohan joined this group when he was 9, and now he helps recruit some of the younger guys. As soon as their workout ends, he and his R.S.S. friends fan out to door-knock for Modi and the B.J.P. What’s interesting is Hari doesn’t talk about jobs, farms or the broader economy — Modi isn’t doing so well on those. Instead, Sabarimala Temple is really the issue. I realize that for most people here, even women, the controversy isn’t about gender equality. It’s about traditions, and who will protect them at all costs. India is a deeply religious country. India is also a secular democracy. These two things are becoming harder to square as religion, and one religion in particular, comes to dominate politics. This moment feels like a battle over very different visions for India’s future. And what happens here in Kerala could predict the direction of the entire country.