West Bengal has turned saffron. Mamata Banerjee's 15-year rule has ended, and the Bharatiya Janata Party (BJP) is set to form its first government in the state. Multiple factors contributed to this decisive political shift, but the most contentious was the revision of electoral rolls through the Special Intensive Revision (SIR) exercise.
How SIR Became the Defining Issue
The SIR of electoral rolls emerged as a central and deeply contested factor shaping the 2026 West Bengal electoral contest. The exercise led to the removal of nearly 91 lakh names, roughly 12% of the electorate, significantly altering the voter base. Of these, over 60 lakh were classified as deceased, while the status of 27 lakh remained pending or under scrutiny.
According to various reports, a large proportion of those affected were Muslims, while sections of the Matua community and many Hindus were also impacted. The BJP framed the SIR as a necessary cleanup of electoral rolls aimed at removing illegal or duplicate entries. However, Mamata Banerjee's Trinamool Congress (TMC) countered this, describing the exercise as systematic disenfranchisement, leading to an open war of words. Regardless of these competing narratives, the scale and spread of deletions reshaped voting trends in a manner that coincided with the BJP's surge across the state. The total voter base dropped from over 7.66 crore to around 7.04 crore, excluding those still under adjudication.
Electoral Data: Mapping SIR Deletions to Outcomes
A closer look at constituency-level outcomes suggests a strong correlation between SIR-linked deletions and the BJP's gains. The BJP improved its performance across seats that witnessed sizeable deletions, irrespective of whether the number of names removed exceeded 25,000 or fell below that threshold. In 169 assembly constituencies where more than 25,000 names were deleted, the TMC had dominated in 2021, winning 128 seats compared to the BJP's 41. This time, however, the balance shifted significantly.
In the remaining 124 seats, where deletions were lower than 25,000, the BJP's tally rose dramatically from 36 in 2021 to 108, marking a three-fold increase. This indicates that the party's gains were not limited to areas with the highest deletions but extended across a broader electoral spectrum influenced by the revision exercise. Among the 38 constituencies where logical discrepancy deletions were the highest, the TMC had won 34 seats in 2021. In the current election, its tally dropped to 22, underlining the erosion of its earlier dominance in these pockets.
Even in high-deletion zones, however, outcomes were not uniform. Among the six constituencies with the highest SIR deletions, the TMC managed to retain only four: Chowringhee, Shamsherganj, Metiaburuz, and Kolkata Port. The BJP captured Jorasanko and Howrah North. Notably, all six seats had been won by Mamata's party in the previous election. Apart from Jorasanko, the BJP made significant inroads in Kolkata and bordering areas, securing victories in Maniktala, Shyampukur, and Cossipore-Belgachhia in Kolkata North, and extending its gains to Rashbehari, Behala East, Bidhannagar, Baranagar, Dum Dum, Dum Dum North, and Rajarhat-Gopalpur. It also won seats in Behala West, Tollygunge, and Jadavpur, all constituencies that had recorded over 25,000 deletions and were previously held by the Trinamool.
Farakka was one of the exceptions. Despite witnessing over 25,000 deletions, the BJP failed to win the seat. Congress candidate Motab Shaikh, whose name had initially been removed during the SIR, successfully appealed through an appellate tribunal, one of 19 set up following Supreme Court directions, and secured restoration of his voting rights. He went on to win the seat by beating BJP candidate Sunil Chowdhuri with a margin of 8,193 votes.
Margins, Deletions, and Electoral Impact
The relationship between deletions and victory margins further underscores the SIR's impact. Of the 187 seats that saw over 5,000 names deleted, the BJP won 119. In these constituencies, the number of excluded voters exceeded the margin of victory in 47 seats. Within the BJP's tally of 119 seats, 28 recorded deletions higher than the victory margin of its candidates. Of these, 26 had been won by the Trinamool in 2021. Among the 20 constituencies with the highest number of deletions after adjudication, the TMC won 13, the BJP six, and the Congress one. However, in the 2021 elections, all 20 had been secured by the Trinamool, highlighting the relative disadvantage it faced this time.
BJP's Security Fortress to Ensure Smooth SIR Process
The SIR exercise was accompanied by an unprecedented security deployment. Over 2.4 lakh personnel from Central Armed Police Forces were stationed across West Bengal, more than three times the levels seen in 2021, creating what the BJP described as a security fortress. The extensive deployment, coupled with tighter oversight by the Election Commission of India, became another key pillar in enabling what the BJP described as free and fair voting in a politically volatile state. At one stage, Mamata approached the Supreme Court over the use of only central government employees as vote-counting supervisors, but the court declined to intervene.
The Matua Factor: Identity, Anxiety, and Consolidation
The Matua community emerged as another critical electoral variable shaped by the SIR exercise. Despite discontent over large-scale deletions and anxieties surrounding citizenship documentation under the Citizenship Amendment Act (CAA), the BJP retained its foothold in Matua-dominated regions such as Bongaon and Nadia. The removal of approximately 1.2 lakh names under SIR triggered social and political tensions in these areas. In Nadia's six assembly constituencies, over 90% of those placed under adjudication did not make it to the final electoral rolls. A similar pattern was observed in Bongaon, where deletion rates ranged from 67% to 88%.
Bagdah became a focal point of this contest, witnessing a high-profile battle within the influential Thakurbari family. BJP candidate Soma Thakur defeated Trinamool MLA Madhuparna Thakur by 34,321 votes. The BJP also retained Bongaon Uttar and secured Haringhata with substantial margins. Despite concerns over exclusion, the Matua electorate, a marginalised Hindu sect primarily comprising the Namasudra scheduled caste group, appeared to consolidate behind the BJP.
Disenfranchisement vs. Electoral Integrity
Clearly, the SIR exercise was the most dominant narrative throughout the elections and will continue to be debated for times to come. The opposition sees SIR as a tool to target and purge its voters, while the BJP justifies it as a much-needed exercise to cleanse electoral rolls.
