Narendra Modi’s landslide victory in India’s polls has swept aside the long-dominant Congress party and left many of the most high-profile politicians clinging on for dear life after staggering electoral losses.

Modi’s campaigners hailed the tidal wave of support for the Hindu nationalist who demolished rivals ranging from India’s top low-caste politician to its most famous anti-corruption activist and a widely admired chief minister.

Nitish Kumar, the former chief minister of Bihar, whose government was feted for engineering a turnaround in the once crime-wracked state, resigned after his party was decimated. Kumar’s Janata Dal (United) party won just two seats while Modi’s Bharatiya Janata Party (BJP) swept the state, one of the country’s most populous and poorest, taking 22 seats.

Political analyst Paranjoy Guha Thakurta described the result as an “all-India tsunami in favour of the BJP”, signifying that most people voted “for a change at the centre, ignoring the otherwise strong track record of regional leaders like Nitish Kumar”.

With the exception of a handful of states in southern and eastern India, which had long lacked a significant Congress or BJP presence, the anti-incumbent vote went to Modi, Thakurta said.

Kumar’s loss at the hands of former BJP allies came less than a year after he cut ties with the party over its decision to field Modi, a popular but divisive figure, as a prime ministerial candidate.

He said Modi’s role as chief minister of western Gujarat state during religious riots in 2002 would alienate voters. More than 1 000 people – mainly Muslims – were killed in the clashes.

The Modi landslide also buried other rivals, including “Dalit Queen” Mayawati, a former chief minister of Uttar Pradesh state and champion of India’s low-caste Dalit community previously known as “untouchables”. Her Bahujan Samaj Party won no seats in the electorally pivotal state.

Moreover, Modi’s success at painting himself as an unifying leader left scant room for opponents who traditionally relied on votes from specific castes, communities or religions.

“We enter a new, less predictable phase of Indian democracy, as more citizens slip loose from their caste, religious or political traditions to vote as individuals,” Sunil Khilnani, the director of King’s College London’s India Institute, wrote.

The results plunged the Congress into its worst crisis in years, leaving party leaders reeling after their seat count slid to 44 from 206 in 2009.

Commentators said Aam Aadmi leader Arvind Kejriwal, who led rousing rallies against graft for months before entering politics in November 2012, overstretched when he took on Modi in a high-stakes battle for a seat in the Hindu holy city of Varanasi. “Kejriwal understood there’s a new-generation Indian whose time had come, but he didn’t have Modi’s political acumen,” said BG Verghese of the Centre for Policy Research in Delhi. – Sapa-AFP