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Kolkata: Electoral outcomes in fiercely contested regions are often decided by razor-thin margins, where every vote counts. In Tamil Nadu, one seat was decided by one vote this time and in Rajasthan and Madhya Pradesh, even in the parliamentary elections, MPs have been elected with the margin of just one vote. Every vote matters.

In West Bengal, the scale of the ‘special intensive revision’ or SIR was staggering. A massive 91 lakh names were struck from the voter list. This included 58 lakh routine deletions under the ASDD (absent, shifted, deleted, and displaced) categories during the draft revision, alongside another 27 lakh voters rendered ineligible following a judicial review of Under Adjudication (UA) cases. When paired with the 1.88 lakh new voter additions in the final roll published on February 28, 2026, the data points to a mathematically decisive role the revision exercise played. 

This exercise becomes important as during the SIR hearings before the apex court, Supreme Court judge, Justice Joymalya Bagchi had said, “If 10% of the electorate does not vote and the winning margin is more than 10%…what will happen? Suppose margin is 2% and 15% of [the] electorate who are mapped could not vote, then maybe…we are not expressing any opinion, but we would definitely have to apply our minds.”

The constituency-level data suggests that the SIR was not just a routine roll-cleaning exercise in West Bengal. Its political significance comes from one central fact – in a large number of seats, the number of deleted voters was larger than the winning margin.

This does not prove that every such result changed because of SIR, but it shows that roll revision directly entered the zone of electoral competitiveness.

Deletions larger than winning margins in 150 seats

The strongest indicator of the SIR having been decisive in dictating the political outcome is in seats where the winning margin was lesser than the total deletions, i.e. the combined ASDD and UA removals. When I combined routine ASDD deletions and the number of UA voters, the total number of deleted voters exceeded the final victory margin in a staggering 150 constituencies. West Bengal has 294 seats in all, which puts the number of such seats over the halfway mark in the assembly.

Among these seats, the Bharatiya Janata Party can be seen to have had a clear advantage and led in 100, while the Trinamool Congress led in 48 and the Congress in two.

In 2021, TMC had won 131 of these seats, and BJP, only 19. 

The two districts bordering Kolkata bore the absolute brunt of the roll contraction, accounting for nearly 30% of all highly affected seats. In the North 24 Parganas, the TMC dominated in 2021 by winning 23 of the 26 affected seats, but the landscape completely flipped in 2026 as BJP captured 21 of them. Similarly, in the South 24 Parganas, the TMC had previously swept all 19 of these seats, but the BJP made deep inroads post-SIR, flipping 10 of them.

Beyond these epicentres, the net roll contraction heavily impacted Muslim-rich and highly competitive districts. In Murshidabad, the TMC’s 2021 tally of 13 out of 15 affected seats fell to just 6, with the BJP picking up 7 and the Congress claiming 2. In Purba Bardhaman, the TMC lost 11 of its 13 previously held seats to the BJP. This trend continued in Howrah and Hooghly; across their 22 combined affected seats, all of which were won by the TMC in 2021, the BJP managed to capture 14 in the recent elections.

Urban centres were not immune to this sweeping pattern either. 

In Paschim Bardhaman, the BJP swept all 8 highly contracted seats, 5 of which were previously held by the TMC. Even in the capital districts of Kolkata North and South, the BJP managed to wrest 6 of the 11........

© The Wire