West Bengal Assembly results | BJP's strategic inroads in Presidency: A new electoral reality for TMC

The battle for West Bengal has once again been decided in the Presidency division, the dense political cluster of Kolkata, Howrah, Nadia, North and South 24 Parganas that accounts for 111 of the state’s 294 assembly seats.

For the BJP, the route to power was always by breaching this Trinamool Congress fortress. In 2026, that breach has come not through a wave, but through a steady erosion that the numbers had been signalling for years. The maximum erosion of the TMC has occurred in the Presidency area, where the BJP has surged from zero to 55 seats, while the TMC’s tally there has more than halved to 51 compared to the last assembly elections.

In 2021, the TMC’s dominance here was near absolute. It won 96 of the 111 seats, while the BJP managed just 14, with the rest going to smaller players. The region had been the backbone of TMC’s rise from 89 seats in 2011 to 91 in 2016, and then peaking at 96 in 2021.

The Presidency division is internally uneven. Kolkata’s 14 seats have historically delivered large margins, while districts like North 24 Parganas (33 seats), South 24 Parganas (31), Nadia (17) and Howrah (16) are far more competitive. In 2021 itself, the BJP’s limited success was concentrated almost entirely in Nadia and parts of North 24 Parganas, where it won nine and the rest of its seats respectively. The party failed to open its account in South 24 Parganas, Howrah or large parts of Kolkata. That distribution mattered.

By 2024, early signs of change had emerged. The BJP began leading in 21 assembly segments across the same region, while the TMC still held a commanding edge in 90. The shift was modest, but it revealed a widening footprint in precisely those constituencies that were once narrowly held.

The 2026 results have turned that incremental gain into a structural shift. The BJP has surged to 55 seats in the Presidency belt, while the TMC’s tally has dropped to 51. The change is sharpest in the very region that once guaranteed the TMC its majority.

The BJP’s gains are not confined to one pocket. While it is ahead in Medinipur, an area with a significant ST and SC population, it has also pushed into key constituencies within the Presidency belt. In Howrah, the party is leading in Howrah Dakshin and Howrah Uttar, with the TMC holding ground only in Howrah Madhya.

The shift is visible in Kolkata as well, where the BJP has taken the lead in Shyampukur, Entally, Beleghata and Maniktala, all seats that were earlier seen as part of the TMC’s urban stronghold.

A similar pattern is emerging in the northern suburban belt, with the BJP ahead in Dum Dum and Dum Dum North. The biggest upset, however, is unfolding in Diamond Harbour, widely regarded as Abhishek Banerjee’s bastion, where BJP candidate Dipak Kumar Haldar has moved ahead.

What explains this reversal is not a collapse of the TMC’s vote base, but the redistribution of margins. In Kolkata, the TMC continues to remain competitive, but the BJP has broken into constituencies that were earlier considered secure. Leads in Shyampukur, Entally, Beleghata and Maniktala signal a shift within the urban core itself. These are not landslide swings, but incremental gains that weaken the TMC’s margin cushion. The more decisive churn, however, lies outside the city.

In Howrah, the BJP has taken the lead in Howrah Dakshin and Howrah Uttar, leaving the TMC ahead only in Howrah Madhya. In the suburban belt of North 24 Parganas, constituencies like Dum Dum and Dum Dum North have tilted towards the BJP areas that were earlier decided by thin margins.

The most telling shift comes from Diamond Harbour, long seen as a TMC stronghold. The BJP’s lead here, alongside turbulence in neighbouring Falta, where repolling has been ordered, captures how volatile even the safest seats have become.

This pattern reflects a broader electoral shift. The BJP has retained its base in north Bengal districts like Alipurduar and Jalpaiguri, but more importantly, it has expanded into new zones, tribal-dominated Medinipur and the margins of the Presidency region. The gains are not uniform, but they are strategically placed.

For the TMC, the problem is one of efficiency. In 2021, it converted its vote share into an overwhelming number of seats because it dominated both strongholds and marginal constituencies. By 2026, that balance has broken. The party continues to command support, particularly in minority-heavy districts like South 24 Parganas and parts of Howrah, but its margins have thinned.

The Presidency division has historically signalled political turning points. The Left Front’s decline was first visible here before it lost power in 2011. The current shift, under an incumbent TMC government, carries similar weight. It does not yet represent a complete reversal, but it marks a clear erosion.

The numbers, taken together, point to one conclusion. The TMC has not lost the Presidency region outright but it no longer dominates it. And in a state where this belt determines the final outcome, that change alone is enough to redraw the political map.