As I watched Donald J. Trump campaigning, I thought, I’ve seen this show before. It was in the 1990s in Bombay (now called Mumbai). And the man playing the Trump part was Bal Keshav Thackeray, the leader of the Hindu nationalist Shiv Sena party, who rode to power on a wave of outrageous stories, bluster, lies, bigotry and showmanship. He died in 2012 after ruling — and ruining — the city I grew up in. The road to understanding Mr. Trump might just lie through understanding Mr. Thackeray, and what became of Bombay.

Mr. Thackeray, who founded his Shiv Sena party in 1966, began his career as a political cartoonist. He had a gift for outrageous parody. His own appearance was a caricature of a Bollywood guru: In his later years, he took to wearing dark shades, an orange robe and a necklace of holy beads, holding a Cohiba in one hand and a glass of warm beer in the other. His party workers, his ministers and the press referred to Mr. Thackeray as “The Supremo.”

He was a master of the art of the outrage, of politics as performance. He would castigate his opponents as “vampires,” “a sack of flour” and various untranslatable epithets like calling South Indians “yandu-gundus.” Periodically, he would express admiration for Hitler, immediately attracting thousands of news pages of free publicity. He regularly called for books and films that he felt were antithetical to Hindu values to be banned. Egged on by his invective, his legions would go out and beat up artists and journalists.

Though Mr. Thackeray neither inherited nor ran businesses as Mr. Trump did, the two men’s support base was remarkably similar in its political contours. The people Mr. Thackeray represented were the native Maharashtrians, the “sons of the soil.” The list of his enemies varied with the seasons, from Communists to South Indian migrants to Gujaratis to Muslims and, eventually, North Indians.

Working-class Maharashtrians felt excluded from booming Bombay, capital of Maharashtra State, as it made the transition from manufacturing to a postindustrial financial and services economy. They resented both the moneyed cosmopolitan elites as well as the North Indian migrants who competed with them for low-skill jobs.

Mr. Thackeray promised to restore their jobs, by threatening mob violence against industrialists who hired non-natives. He promised to make Maharashtra great again by reversing the clock: His idol was the 17th-century warrior-king Shivaji, who held the Mughal emperors at bay. He demanded the requirement of a visa to enter Bombay.