Rather, he said, “it seems that the public is still enamored of Modi.”

Mr. Modi swept into power in 2014 on a wave of public support for his development agenda and on disaffection with the previous governing coalition, led by the Congress party. Though economic changes have been intermittent, partly because of lack of support in Parliament from other parties, eight in 10 Indians have a positive view of the economy, and about two-thirds are satisfied with the way things are going in India generally, according to the survey.

Part of the good will could be explained by the country’s economic growth; an annual rate of 7.1 percent for the most recent quarter makes India’s the fastest-growing large economy in the world. But significant economic alterations, including those regarding land acquisition and labor, which are seen as crucial for modernizing India’s economy and expanding its formal work force, have stalled because of lack of support in Parliament. In one sign of progress, however, the government in August pushed through the Goods and Services Tax, a uniform code that should do away with overlapping state and federal taxes, helping to unify the economy.

“People are not willing to give up on him on the economy so quickly,” said Shekhar Gupta, a journalist and political commentator, adding that Mr. Modi’s frequent speaking engagements may have helped bolster his popularity. “After a long time, Indians have a leader who’s speaking to them directly and speaking to them all the time.”

The pollsters interviewed 2,464 randomly selected adults from April 7 to May 24 in 15 states and in New Delhi, the capital. The poll has a margin of error of plus or minus three percentage points.

Though many expressed support for Mr. Modi and for his party, increasing polarization between backers of Bharatiya Janata and those of the Congress party was apparent in the survey. Those differences were particularly stark on domestic issues like corruption, unemployment and help for the poor, where support from Congress party backers for Mr. Modi’s efforts has fallen since last year.