Sir, yes sir: How voter deletion affected West Bengal elections

West Bengal has turned to saffron. Mamata Banerjee15 years of rule has ended, the Bharatiya Janata Party (BJP)bjp) is ready to form the first government of the state.So what prompted a decisive political shift in the state’s electoral landscape? Well, there are many factors that contribute to this outcome, but the most controversial is the modification of the Electoral Register – the SIR.

How SIR became the decisive issue in the election

The Special Intensification Revision (SIR) of the electoral roll has emerged as a central and controversial factor shaping the contest for the 2026 West Bengal elections. The operation resulted in nearly 9.1 million names being removed – about 12% of the electorate – significantly changing the electorate ahead of the vote. Of those, more than 6 million are listed as dead, while the status of 2.7 million remains pending or under review.According to various reports, a large portion of those affected are Muslims, while sections of the Matua community and many Hindus have also been affected. The BJP sees the SIR as a necessary cleansing of the electoral rolls aimed at eliminating “illegal” or duplicate entries. But Mamata’s party disputed this and described the approach as systematic disenfranchisement, leading to a public war of words.Regardless of these conflicting narratives, the scale and spread of expungements reshaped voting trends in a manner consistent with the BJP’s surge across the state. The total number of voters fell from over Rs 766 crore to about Rs 704 crore, excluding those still under adjudication.

Election Data: Mapping SIR Deletions to Results

A closer look at the constituency-level results shows a strong correlation between SIR-related deletions and gains for the BJP.The BJP’s performance improved in seats that were slashed, whether the number removed was above 25,000 or below that threshold. In 2021, the TMC dominated 169 assembly constituencies (over 25,000 names were dropped), winning 128 seats, while the BJP won 41 seats. This time, however, the balance has shifted significantly.Of the remaining 124 seats, fewer than 25,000 were removed, with the BJP registering a three-fold increase in seats to 108 from 36 in 2021. This suggests that the party’s gains were not limited to the areas with the most removals, but also extended to the wider electoral sphere affected by the revision campaign.

Of the 38 constituencies where the most “logical differences” were removed, TMC won 34 seats in 2021. In this election, its vote count fell to 22, underlining the erosion of its earlier dominance in these areas.However, even in high deletion areas, the results were inconsistent. Of the six constituencies with the highest number of SIR deletions, the TMC retained only four constituencies: Chowringhee, Shamsherganj, Metiaburuz and Kolkata Port, while the BJP captured Jorasanko and Howrah North. Notably, Mamata-led party won all six seats in the last elections.Apart from Cholasankoh, the BJP made significant inroads in Kolkata and border areas, notching victories in Maniktala, Shyampukur and Kosipore-Belgazia in north Kolkata and extending its gains to Rashid Behari, Behala East, Bidnagar, Baranagar, Dumdum, Dumdum North and Rajarhat-Gopalpur. It also won the seats of Behala West, Tollygunge and Jadavpur – all constituencies with more than 25,000 seats removed and previously held by the Trinamool.Faraka is one of the exceptions. Despite deleting over 25,000 seats, the BJP failed to win seats. Congress candidate Motab Shaikh, whose name was initially removed during the SIR, successfully appealed through the Court of Appeal (one of the 19 appellate tribunals established on Supreme Court directives) and secured the restoration of his voting rights. He later won the seat by 8,193 votes, defeating the BJP candidate Sunil Chowdhuri.

Margins, deletions and electoral effects

The relationship between removal and win rate further emphasizes the impact of SIR. Of the 187 seats from which more than 5,000 names were removed, the BJP won 119 seats. In these districts, the number of excluded voters exceeded the victory margin of 47 seats.Of the 119 seats held by the BJP, 28 seats were pruned by more than the margin of victory of its candidates. 26 of them were won by the Trinamool in 2021.Of the 20 constituencies with the highest number of deletions after the ruling, the TMC won 13, the BJP six and the Congress one. However, in the 2021 elections, the Trinamool won all 20 seats, highlighting the relative disadvantage it faced this time.

BJP’s ‘security bastion’ ensures smooth SIR process

The SIR exercise was accompanied by unprecedented security deployment. More than 240,000 Central Armed Police Force personnel are stationed across West Bengal, more than three times the number in 2021, creating what the BJP calls a “security bastion”.The widespread deployment, coupled with tighter oversight by the Election Commission of India, becomes another key pillar in achieving what the BJP calls “free and fair voting” in the politically volatile state.Mamata at one point approached the Supreme Court over the use of only central government employees as vote counting monitors, but the court refused to intervene.

Matua Factors: Identification, Anxiety, and Reinforcement

The Matua community emerged as another key electoral variable shaped by SIR activities. Despite dissatisfaction and anxiety over the mass deletion of citizenship documents under the CAA, the BJP has maintained a foothold in Matua-dominated districts like Bangaon and Nadia.The SIR removed around 120,000 names, sparking social and political tensions in the areas. In Nadia’s six constituencies, more than 90% of those who were adjudicated did not make it to the final electoral roll. A similar pattern was observed in Bongaon, with missing rates ranging from 67% to 88%.Baghdad became the focal point of the contest, witnessing a high-profile struggle within the influential Takubari family. BJP candidate Soma Thakur defeated Trinamool MLA Madhuparna Thakur by 34,321 votes. The BJP also retained Bongaon Uttar and locked Haringhata by a handsome margin.Despite fears of exclusion, Matua voters – a marginalized Hindu sect largely made up of the Namasudra scheduled caste group – appear to have consolidated support for the BJP.

Disenfranchisement and electoral integrity

Clearly, the SIR exercise was a dominant topic throughout the election process and will continue to be debated in the future. The opposition sees the SIR as a tool to target and cleanse voters, while the BJP sees it as a much-needed move to clean up the electoral rolls.