In achieving its historic first foray in the last fortress of West Bengal, Bangladesh became the Bharatiya Janata Party’s most potent political metaphor.

The collapse of Sheikh Hasina’s government in August 2024 handed Narendra Modi’s party precisely the external crisis it needed. Images of mobs attacking Hindu homes, vandalising temples and Islamist groups reoccupying public space in Bangladesh flooded Bengali television channels and WhatsApp networks.

West Bengal’s media ecosystem, especially Bengali-language outlets sympathetic to the BJP, converted every episode of unrest across the border into a warning about Bengal’s future.

The BJP understood something the Trinamool Congress probably did not. Bengal’s politics may still speak the language of class and culture, but its electorate has become increasingly responsive to the language of insecurity.

‘Illegal immigration’ from Bangladesh, once treated as a bureaucratic or humanitarian issue, was recast as a civilisational threat. BJP leaders repeatedly argued that unchecked migration was altering Bengal’s demography district by district.

Border regions such as North 24 Parganas, Nadia, Malda and Murshidabad became laboratories for this narrative. Every welfare queue, every voter-roll controversy and every communal flare-up was folded into the same accusation: Mamata Banerjee had traded border security for Muslim votes.

The data made the rhetoric politically combustible. Census figures over several decades have shown disproportionately high Muslim population growth in several border districts compared with the state average.

The BJP relentlessly weaponised these trends, presenting them as evidence of state-sponsored infiltration. The party’s campaign speeches rarely distinguished between undocumented migrants and Bengali Muslims. That ambiguity was deliberate. It allowed anxieties about migration to bleed seamlessly into anxieties about identity.

The Trinamool Congress was disastrously slow to recognise how deeply this narrative had penetrated Hindu middle-class and lower-caste voters. Mamata Banerjee continued to rely on a coalition built around welfare populism and minority support. But welfare schemes cannot easily compete with existential fears.

The BJP converted the election from a judgment on governance into a referendum on belonging.

Muhammad Yunus, the Nobel laureate leading Bangladesh’s interim government, became collateral damage in this political reconstruction. Internationally, Yunus was often portrayed as a democratic reformer stabilising a country after Hasina’s fall.

In West Bengal’s political discourse, however, he was depicted very differently: weak, indecisive and incapable of restraining Islamist forces. Bengali news channels repeatedly juxtaposed Yunus’s statements with footage of anti-Hindu violence and Jamaat-e-Islami rallies.

The visual grammar mattered more than factual nuance. A perception hardened that Bangladesh under Yunus was drifting into majoritarian Islamic politics.

That perception became electoral ammunition for the BJP. The party argued that Mamata Banerjee’s politics of minority accommodation mirrored the very permissiveness that had allegedly enabled Islamist resurgence in Bangladesh.

In rally after rally, BJP leaders suggested that Bengal was approaching a demographic and political tipping point. Their speeches carried an unmistakable subtext: Vote BJP, or Bengal risks becoming ‘West Bangladesh’.

The BJP’s most effective constituency in this campaign was not upper-caste Hindus but refugee communities with direct memories of Bangladesh. The Matuas, many of whom trace their displacement to communal violence in East Pakistan and later Bangladesh, became central to the party’s strategy.

Narendra Modi’s repeated references to persecuted Hindus across the border were not abstract ideological appeals. They resonated with communities whose family histories are rooted in migration, dispossession and insecurity.

The Citizenship Amendment Act transformed these emotions into hard electoral arithmetic. By promising fast-track citizenship to non-Muslim migrants from Bangladesh, Pakistan and Afghanistan, the BJP effectively created a political compact with refugee Hindus.

The Trinamool’s opposition to the law allowed the BJP to portray Banerjee as indifferent, if not hostile, to Hindu refugees. In Bengal’s border politics, symbolism often outweighs policy detail. The BJP grasped that instinct better than its rivals.

Jamaat-e-Islami’s growing visibility in Bangladesh after Hasina’s fall further sharpened the BJP’s campaign. Reports of Jamaat mobilisation, student Islamist activism and anti-India rhetoric circulated widely in West Bengal.

In districts with porous social and familial ties across the border, these developments were followed obsessively. The BJP amplified every indication of Islamist resurgence as evidence that secularism in Bengal was naïve at best and suicidal at worst.

This strategy was particularly effective because Bengal had already experienced years of low-grade communal polarisation. Riots in Basirhat, tensions in Howrah and repeated controversies over Ram Navami processions had gradually eroded the state’s reputation for communal moderation.

The BJP did not create these anxieties from scratch. It nationalised and systematised them. Bangladesh simply provided the external theatre through which local insecurities could be dramatised.

The transformation is historically striking. Bengal was once the intellectual heartland of Indian secular nationalism. For decades, overt religious polarisation struggled to gain traction against the state’s entrenched Left-liberal political culture.

Yet the BJP succeeded where earlier Hindu nationalist formations failed because it fused Hindutva with Bengali vulnerability. Rather than presenting Hindu nationalism as muscular triumphalism, it presented it as self-defence.

This was the campaign’s crucial innovation. The BJP did not ask Bengali Hindus to dominate minorities; it asked them to fear becoming minorities themselves. Bangladesh supplied the emotional evidence for that proposition.

Every attack on a temple in Khulna or Rangpur became politically useful in Kolkata and Siliguri. Every report of Hindu flight from Bangladesh reinforced the BJP’s claim that demographic complacency leads eventually to civilisational retreat.

The result was a profound reframing of Bengal’s politics. Economic stagnation, unemployment and industrial decline receded behind identity anxieties. The election ceased to be about roads, jobs or inflation.

It became about borders and religion…as well as about survival. The BJP succeeded because it made voters feel that history itself was crossing the border.