LUCKNOW, India — In their 31 years of marriage, Seema and Sanjive Khanna have fought many times, the way couples do, over the house or the children or their finances.

But nothing has divided them as bitterly as Prime Minister Narendra Modi in the current Indian election. To Seema, Modi can do no wrong, but to Sanjive, he has done nothing right.

Sometimes, after they argue about Modi, they don’t speak to each other for hours. To keep the peace on their daily walks around the neighborhood, they instituted an informal rule: no talking about politics.

While such bitter political divisions are all too familiar in the United States, they are relatively new in India, the world’s largest democracy. In the seven-phase election that ended here Sunday, India’s politics have increasingly mirrored the United States’: Every issue is filtered through a partisan lens, social media is the scene of rancorous exchanges, and disagreements over politics have strained relationships.

“People had different opinions earlier, as well, but the atmosphere was never so hostile,” said Niti Saxena, 47, a women’s rights activist in Lucknow. “This is not healthy.”

And at the heart of the growing divide stands the towering figure of Modi, who inspires either fervent loyalty or deep distrust, not unlike President Trump.

Modi was elected in a landslide victory in 2014 and is seeking reelection. He leads the Bharatiya Janata Party, a center-right political party built around Hindu nationalism, the idea that India — home to a diversity of religions — is fundamentally a Hindu nation, not a secular republic. Exit polls on Sunday indicated that Modi and his BJP-led coalition would return to power. Official results will not be announced until Thursday.

The ugliness in living rooms and around dinner tables reflects the polarization “coming from the top,” said Ashutosh Varshney, a political scientist at Brown University. Modi’s view of politics divides people into friends and enemies, he said. 

“If you have that spirit, you will have bitterness instead of competitiveness,” Varshney said. “There is no space for neutral conversation.”

Research confirms that Indian politics is growing more polarized. A 2017 survey by the Pew Research Center found there was a growing partisan gap between supporters of the BJP and the opposition Indian National Congress party when it came to their views of Modi.

Of course, there are differences between India, with its multitude of parties and parliamentary democracy, and the two-party system in the United States. Still, Modi has worked to turn Indian elections into presidential-style contests, urging voters to focus on him rather than a party or representative in Parliament.

“Earlier it was about the parties, and this is about Modi,” said Ritu Priya, a program manager for a German foundation in Delhi who has fought repeatedly with her father about politics. “Sometimes you think it would be nice if you could have a meaningful conversation. You cannot. Everything will end up a disaster.”

The growing polarization was on display on a recent weekend afternoon at the Khanna household in Lucknow, the capital of Uttar Pradesh, the country’s biggest state. Just before lunchtime, Seema, 53, and Sanjive, 57, sat in their living room and chatted with their daughter and her husband. Talk veered to politics within seconds.

“You know that quote about not being able to fool all the people, all the time? Modi has proved it wrong,” Sanjive said.

At least Modi is a strong leader, unlike his predecessor from the opposition Congress party, who was “sitting with a lollipop” doing nothing, Seema retorted. “Modi’s got spine.”

Sanjive says that under Modi, India’s democracy has degenerated into dictatorship. Seema disagrees vehemently. When Sanjive calls Modi a “con artist” and criticizes him for abandoning his wife, Seema gets visibly upset.

“I don’t want to look at him right now,” she said, turning away from Sanjive.

Their daughter Kareshma, who runs a pharmaceutical start-up and describes herself as apolitical, finds her parents’ behavior mystifying. “I can’t understand how they can fight like cats and dogs over politics,” she said.

In the new political environment, Indians have developed strategies for dealing with friends, family members and colleagues with differing views: Either stick with your own kind or avoid talking about Modi altogether.

At a recent wedding, Sanjive described being outnumbered by Modi supporters in the family. “I consciously chose to sit with the few who shared my beliefs,” he said. “I didn’t want the occasion to turn ugly.”

This shrinking space for harmony is evident at dinner tables, too. In another leafy neighborhood of Lucknow, the Singh family assembled on a recent evening at patriarch Chandra Bhal’s house.

A retired army officer, Singh has admired only two Indian prime ministers in his lifetime — one is Modi and the other is Indira Gandhi of the Congress party, popularly dubbed the “Iron Lady,” who helped liberate Bangladesh from Pakistan in 1971.

Singh especially approved of Modi’s decision to launch an airstrike on an alleged terrorist camp in Pakistan after an attack in ­Indian-controlled Kashmir in February.

“To survive in this world, you need a powerful leader. See, nobody messes with the United States or Russia,” Singh said.

His daughter Niti Saxena, the women’s rights activist, and granddaughter Shubhangi, 29, are outraged. They worry about the risk of war and accuse Modi of politicizing the army by asking for votes on the campaign trail in the name of the airstrikes.

“It’s shocking. It is as if Modi is the country!” Shubhangi said.

Voices rise, fingers are pointed, and people start talking over each other. Then, in deference to Singh, Shubhangi and Niti fall silent. Someone says, “Let’s serve dinner.”

Priya, the program manager who lives in Delhi, said that the last time her parents came to visit a few months ago, her father and her elder brother got into a heated argument over politics that lasted several hours. Her father, a Modi enthusiast, told his children, both Modi detractors, that he felt ashamed of them.

She said her father’s views became more entrenched in recent years, ever since he retired and began consuming a steady diet of pro-Modi television channels and reading partisan forwarded messages on WhatsApp.

But Priya added that the bitterness cuts both ways. “I’ve also become a bit intolerant,” she said. “I won’t say it’s only them. If they say something wrong, I cannot tolerate it, either.”

Slater reported from Delhi.