Modi’s Party Doesn’t Control All of India. But He’s Working on It.

It is the final frontier for India’s most powerful leader in decades.

Narendra Modi, over his 10 years as prime minister, has made it his mission to turn a complex and diverse country of 1.4 billion people into something approaching a monolith dominated by his sweeping Hindu nationalist vision.

The news media, the national legislature, civil society, sometimes even the courts — all have largely been bent to his will. But one critical group of holdouts remains: some of India’s richest states, the engine of its rapid growth.

The future shape of the world’s largest democracy — and its economic trajectory — may rest on the power struggle that has ensued.

Mr. Modi, who is well placed to win a third term in a national election that will begin on April 19, is wielding an increasingly heavy hand in what his opponents call an unfair effort to drive out the governments of the states his party does not control.

They accuse Mr. Modi’s administration of delaying federal money for major projects; of jailing or hounding opposition leaders while shielding anyone who joins the prime minister’s party; of obstructing the delivery of basic services; and of throwing state politics into chaos.

The tensions are tearing at India’s delicate federal formula of power sharing and political competition, the glue holding the country together across 28 states and eight territories.

Regional leaders have described the behavior of the central government, which holds more power than in federal systems like the United States’, as that of a colonial overlord. In the south, the most developed and innovative part of India, officials have spoken of a “separate nation” for their region if the “patterns of injustice” continue.

Mr. Modi and his lieutenants have in turn accused the state leaders of harboring a “separatist mind-set” and pursuing politics that could “break the nation.”

India’s move toward more centralized governance could hurt its overall growth, analysts say, as such efforts have done in the past. Big national spending programs focus on basic development problems that the south mostly solved decades ago. If that region’s freedom to make investments based on its own needs is restricted, the effects could be far-reaching.

“It is ultimately self-destructive,” said P.T. Rajan, a cabinet minister in the government of the southern state of Tamil Nadu.

Mr. Modi offers a simple solution: for the states governed by parties other than his Bharatiya Janata Party, or B.J.P., to come on board.

He often draws on automotive terminology to make his pitch. Those states, he says, could benefit from what he calls a “double engine” government, with one party — his own — working in sync at both the national and state levels.

If they do not comply, the states get wrench after wrench thrown into the works of their governments, officials say, making it difficult for them to deliver on election promises. The B.J.P., relentlessly expanding its base, waits in the wings.

Last month, the chief ministers of about a half-dozen states staged a dramatic demonstration near the seat of federal power in New Delhi.

With posters reading, “Our Blood, Our Sweat, Our Tax,” hanging behind them, they complained that Mr. Modi was using his outsize control over the distribution of revenues collected across India to entrench his party and hobble their own state governments.

At the same time, Mr. Modi was on a final lap of the country before the announcement of the election dates. In opposition states, he combined promises of billions of dollars in infrastructure and welfare projects with scathing criticism of the local parties.

They are scathing of him, too. They have repeatedly sued state governors appointed by New Delhi, who hold largely ceremonial roles, over complaints that they are stalling the work of elected governments.

“You’re playing with fire,” India’s chief justice, Dhananjaya Yeshwant Chandrachud, told the central government after the governor in the opposition-controlled state of Punjab repeatedly prevented legislative work. “Will we continue to be a parliamentary democracy?”

In Tamil Nadu, officials said they were struggling to expand a subway line in the capital city, Chennai, because Mr. Modi’s administration was dragging its feet on New Delhi’s share of the funding.

In Kerala, on India’s southwestern coast, the state government is suing the Modi administration over what it says are arbitrary borrowing limits that have thrown the state’s budget into disarray and delayed payments.

In the western state of Maharashtra, home to Mumbai, India’s financial and entertainment capital, Mr. Modi’s officials have splintered the state’s two largest parties through a mix of pressure from investigative agencies and offers of incentives. Such “smash and grab” politics, as critics have branded it, has paved the way for the B.J.P. to emerge as a kingmaker in a coalition government.

In the Delhi capital region, the B.J.P. appears hellbent on destroying a smaller party that swept to power promising to improve basic services. The territory’s elected government has been stripped of important powers, and federal agencies have bogged down the top leaders of the party, Aam Aadmi, in corruption cases.

The party’s deputy leader and a key cabinet minister have been in jail for over a year. On Thursday, in a dramatic nighttime raid, government agents arrested Arvind Kejriwal, the party’s leader and Delhi’s chief minister, whom they have accused of financial crimes. He is the first serving chief minister to be arrested..

The bitter political dispute in Delhi is evident in overflowing sewage in parts of the city and long lines outside government hospitals.

Aam Aadmi sought to improve hospitals in part by relying on outside contractors to enter patient data. But the plan has been caught in the crossfire between Mr. Modi’s officials and the territory’s elected government, and the contractors pulled their staff from many hospitals after salaries were delayed for months.

“In their political fighting, it is the public that suffers,” said Adit Kumar, a cloth-seller who has diabetes, who, along with his wife, was waiting outside a crowded hospital in New Delhi one recent day.

Saurabh Bhardwaj, an Aam Aadmi official in Delhi, said Mr. Modi’s intention was clear: to push the country toward one-party rule.

“You reduced the state government’s work so much that people start saying that it’s better to bring the B.J.P. and only they can deliver,” Mr. Bhardwaj said. “That means the federal structure will collapse.”

The biggest federal-state fault line pits the more prosperous south against Mr. Modi’s support base in the north.

Except for a brief period in the state of Karnataka when the B.J.P. took control by orchestrating defections, the party has been unable to win power in the five southern states.

Officials there say that Mr. Modi is trying to hold them back for their refusal to buy in to his brand of politics, including his party’s stirring of Hindu-Muslim tensions and its push to make Hindi — which is not widely spoken in the south — a national language.

The resentment is amplified by complaints that the south gets proportionally less in return for the tax money it sends to New Delhi. Because the northern states have large populations and are far behind in basic development, they get a larger share of the revenues.

There are also serious concerns in the south that the redistribution of parliamentary seats once a long-delayed national census is finally held will punish the south for its success in reducing birthrates, a key to its relative affluence.

With its earlier investments in infrastructure, education and public health — the result of a unique mix of political, cultural and historical differences in the south — the region is better placed to propel India’s ambition for high-end manufacturing. Mr. Modi’s politics-driven approach, his opponents say, could undercut his ambitions for building India into a major economic power.

The federal finance minister, Nirmala Sitharaman, rejected claims that revenues were being unfairly distributed, saying the central government was “releasing, and releasing on time,” the states’ share.

“We want every part of the country to prosper,” Mr. Modi said in Parliament after the state leaders’ protest in New Delhi, casting himself as a strong proponent of “competitive, cooperative federalism.”

In pressuring state governments, analysts say, Mr. Modi is simply exploiting structural flaws in India’s Constitution, which created a republic — a quasi-federal union of states — after the British left in 1947.

The Indian National Congress party, which ruled over India uncontested in the first decades after independence, abused the outsize constitutional powers given to the central government over fiscal matters to quash the rise of competitors.

Starting in the late 1980s, however, the decline of Congress ushered in an era of coalition politics, with regional parties finding representation in New Delhi.

This was also the period when India opened its heavily centralized economy to the free market. As growth followed, the distribution of resources was subject to more push and pull between the central and state governments.

“The emergence of regional powers made the center commit to certain principles,” said Kalaiyarasan A., an assistant professor at the Madras Institute of Development Studies. “The 1990s was a golden period of federalism.”

Today, Mr. Modi is seeking to remake Indian federalism with his “double engine” push.

In opposition-held states, Mr. Modi has offered infrastructure and welfare projects, branded with his name or that of his office, to pitch himself as India’s only driver of development and growth.

In engaging in joint projects, the state parties face a political cost: They will get the money only if they agree to the Modi branding.

And if they resist?

In 2022, Ms. Sitharaman, the finance minister, stopped at a shop in the southern state of Telangana that distributed rice rations as part of a joint program in which the central government provided the larger share of the funding. Mr. Modi’s picture was not displayed there. Ms. Sitharaman lashed out at state officials.

“This is the work that our prime minister is doing for his people,” Ms. Sitharaman said. “Our people will come and install the prime minister’s photo, and you will, as district administrator, ensure that shall not be removed, that shall not be torn, that shall not be affected.”