As an election nears, political strife between Prime Minister Narendra Modi and opposition-held states is straining the federal formula that holds India together.

By Mujib Mashal and Hari Kumar

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 part…

This story was originally published in nytimes.com. Read the full story here.