The Bharatiya Janata Party's (BJP) political juggernaut has been on a roll since 2014, taking one Indian state after the other.
However, the eastern state of West Bengal, with a population of more than 91 million and its own brand of left-wing politics, remains one of the few that have staved off the onslaught.
The BJP hopes to breach this rampart on May 2, when results for the ongoing state election in West Bengal are announced along with those for Assam, Tamil Nadu, Kerala and Puducherry.
Polling in the state began on Saturday and will go on till April 29.
It is one of the most significant state elections in India in recent years and campaigning has been intense, with Prime Minister Narendra Modi addressing several party rallies in the state.
His party is up against the All India Trinamool Congress (AITC) led by the state's Chief Minister Mamata Banerjee. She is one of the country's toughest political leaders, and her popularity has proved to be a fierce match for Mr Modi's appeal in West Bengal.
Not once has BJP ruled this state, and a victory here will be a coveted win, especially when the federal government has been facing criticism over issues such as its handling of the ongoing farmers' protests and falling rankings in international democracy indexes.
"They would be really looking for an electoral win to reconfirm their strength and popularity," said political commentator Saba Naqvi, who described the state as one of the "last citadels of the opposition".
"A win in Bengal would be an emphatic restatement of the BJP's capacity to work the electoral system to their advantage," she said.
In the 2019 General Election, the BJP won 18 of the state's 42 parliamentary seats, up from two in 2014. Its share of the popular vote also shot up to 40.6 per cent from 16.8 per cent, which has emboldened the BJP this time round with optimism for a win in a state that has been out of its reach.
It holds just three seats in the state assembly, but its leaders claim the party will win more than 200 seats this time.
Dr Biswanath Chakraborty, a professor of political science at Rabindra Bharati University in Kolkata, pointed out: "The BJP may fail to make the government in this election but it has been very successful in injecting its ideology among the masses in Bengal."
The AITC, on the other hand, has been in power in West Bengal since 2011, when it dislodged a government led by the Communist Party of India (Marxist) that had governed the state for 34 years.
Ms Banerjee, whose party holds 211 of 295 seats in the outgoing state assembly, is seeking a third consecutive win even as she battles accusations of corruption.
The campaigning phase has been bitter, with many high-profile defections from the AITC to the BJP, leading one senior leader from AITC to describe the BJP as "Borrowed Janata Party".
Mr Modi, in a recent rally, annexed AITC's "khela hobe" (game is on) battle cry with the declaration of "khela shesh hobe" (game will be over) for his rival party.
BJP's progress comes amid an unprecedented rise in communal polarisation in West Bengal, where Muslims account for more than 27 per cent of the population.
"The AITC is responsible for launching identity politics in West Bengal with its brand of Muslim appeasement - something the BJP reacted to with its mobilisation of Hindus," Dr Chakraborty said.
Meanwhile, the AITC, which blames the BJP for stoking communal tensions to gather votes from Hindus, has sought to portray the battle as one between Bengalis and "outsiders", in a reference to the BJP's top Hindi-speaking leaders. It even describes Ms Banerjee as "Bengal's own daughter".
A win for the AITC will reinforce Ms Banerjee's stature as a national leader.
Incidental violence was reported on the first day of polling on Saturday, and several BJP and AITC party workers had also been killed during the campaign.
Dr Chakraborty said the use of violence has become structurally more embedded in the state's politics. "I am concerned there could be much more violence after the election," he added.
Polling also began on Saturday in Assam, where the incumbent BJP is seeking to retain power.
