2014: The Election that Changed India. By Rajdeep Sardesai. Penguin Viking; 372 pages; $20 and £16. Buy from Amazon.com, Amazon.co.uk

WITH a couple of weeks to go in India’s recent election, a six-week marathon involving more than 800m registered voters in 28 states, strategists from the Bharatiya Janata Party (BJP) felt that their champion, Narendra Modi, needed something extra. Using more than 2,500 technicians, they launched a campaign of daily hologram shows. These brought Mr Modi, in shimmering 3D, live to 1,300 locations and an estimated 7m people over 12 days. Each daily showing cost millions, says Rajdeep Sardesai, a well-known Indian television journalist, in a new book about the election.

Whether it has changed the country is not yet clear. But the campaign was unprecedented, not least for the exorbitant sums spent by the BJP. This helped the Hindu nationalist party transform its fortunes. In the 2009 election the BJP did so badly some predicted it was finished. Middle-class Hindus were alarmed by the religious violence the party often stirred. Yet this year it bagged 282 of the 350-odd seats in which it stood even a narrow chance of victory. This made it the first party other than Congress, India’s historic freedom-fighting party, to win a majority—and Mr Modi one of the most powerful prime ministers in Indian history.

Mr Sardesai knows Mr Modi better than most journalists. He first met him in 1990, when the prime minister was a Hindu ascetic and political activist who laughed often, though never with his eyes. This lends subtlety and authority to Mr Sardesai’s portrayal of a politician who tends either to be slavishly lauded, for his success as an administrator in Gujarat, or castigated as a Hindu chauvinist, who presided over one of India’s worst incidents of communal bloodletting. For Mr Sardesai, who reported on that violence, in which over 1,000 people, most of them Muslim, were slaughtered while police stood by, the two manifestations are related. Mr Modi sought to project himself as a development guru, he suggests, partly to escape his association with murder and mayhem. Yet India’s prime minister remains, even for Mr Sardesai, a mysterious figure.

In hologram or the flesh, Mr Modi is a brilliant public speaker, capable of seemingly endless Hindi epithet and rhyme. Yet the main force behind the “Modi Wave” was the weakness of Mr Modi’s opponents. After leading a succession of feuding and corrupt coalitions, the Congress Party was detested. In Rahul Gandhi, the latest scion of the Nehru-Gandhi dynasty, it also had a poor prime-ministerial candidate. He emerges from Mr Sardesai’s account as spoilt, complacent and tin-eared to the great changes afoot in the country. In one scene Mr Gandhi commiserates with migrant workers from Uttar Pradesh who, he said, were being forced to “go and beg in Mumbai”. By maligning them as beggars, Mr Gandhi illustrated his party’s dreadful failure to comprehend the aspirations of millions of hardworking Indians.

The BJP does understand them. The government has made promising moves to shift the focus of Indian politics from dole handouts to economic growth. With its strong majority and Mr Modi’s managerial prowess, the party has an historic opportunity to improve India. But given its record of manipulating religious hatred, it could also do great harm. Mr Sardesai detects one or two troubling early signs. The BJP minority-affairs minister, for example, has suggested that for the purpose of national identity all Indians can be described as Hindu, including the quarter of a billion who are not. Mr Modi let that go uncorrected. Yet the vigour of Indian democracy stands against the extremists. Mr Sardesai, a bold and even-handed commentator, is part of that.