New Delhi: The 2025 Bihar Assembly election is over, leaving behind numbers that show a fundamental shift in the state’s political behavior. Turnout reached a provisional 66.91% across two phases. That figure is a 9.62 percentage point jump from the 57.29% in the 2020 election and the highest turnout in a Bihar Assembly election since 1951.The turnout number alone doesn’t tell the full story. The data reveals a fundamental shift in who voted, and points to the reasons why.A mandate defined by womenWomen’s participation defined this election. The turnout among women was 71.6%; whereas for men, it was 62.8%.This 8.8-point gap is significant. In absolute numbers, 2.51 crore women voted, compared to 2.47 crore men. This means 4.34 lakh more women voted than men.This happened even though men are a majority of the electorate. The final voter list contained 3.93 crore men and 3.51 crore women. Women were 47.2% of the electorate, but they cast 50.4% of the votes. The gender ratio of actual voters was 1,018 women for every 1,000 men.This is the peak of a 15-year trend. Data shows female turnout first surpassed male turnout in the 2010 Assembly election. The gap widened in 2015 (60.48% vs 53.32%) and held in 2020 (59.69% vs 54.45%). The 2025 election is the moment this long-building participation reached a critical, mandate-defining mass.Factor 1: The electorate revision and its effectsThe Special Intensive Revision (SIR) of electoral rolls, conducted before the election, provides key context. This administrative process changed the electorate’s composition and became a political issue.The SIR dropped the voter list’s gender ratio from 907 women per 1,000 men on the 2024 Lok Sabha rolls to 892 for this election. This indicates a higher net deletion of women’s names from the rolls. Based on these ratios, the process led to an estimated net deletion of over 5.7 lakh women.A report by The Hindu noted that many of these deletions, especially among women aged 18-29, were reasoned as “permanently shifted,” which may be linked to women moving after marriage.The opposition termed the process ‘vote chori‘ (vote theft), framing it as an attempt at disenfranchisement. This narrative of a threatened right to vote may have created a powerful incentive to participate. The effort voters had to put to check their names and re-enroll may have hardened their resolve to cast a ballot.Reducing the female electorate also has a direct statistical impact. Turnout is calculated as a percentage of registered electors (the denominator). By shrinking this denominator for women, the SIR artificially inflated their turnout percentage. A calculation against the pre-SIR base suggests a turnout closer to 70.5%. The 1.15 percentage point difference represents this statistical inflation. This does not alter the surge in absolute numbers but adds context to the official percentage.Factor 2: Catalysts for a new electorateSeveral converging factors appear to have motivated voters: First was the grievance over the SIR. Second was a direct economic promise – the proposed payment of Rs 10,000 to women under the Mukhyamanthiri Mahila Rozgar Yojana.The 2022 caste survey showed that 34.13% of households survive on Rs 6,000 a month or less, with poverty concentrated among Scheduled Castes (42.93%) and Extremely Backward Classes (EBCs) (33.58%). For these households, a payment of Rs 10,000 is more than a month’s income – a major economic event, not just a promise.Third was the infusion of new voters. The electoral roll included 14.01 lakh first-time voters aged 18-19, a bloc with no prior voting record.Fourth was the role of on-the-ground mobilisers. The Election Commission itself noted the deployment of about 1.80 lakh Jeevika Didis as volunteers, a grassroots women’s network that could help with voter information and turnout.These factors appear to have activated a large segment of the dormant/neglected resident population. The male turnout of 62.8%, also an increase, suggests a broader mobilisation that may have motivated some migrant workers to return and resident men to vote in higher numbers. The entry of new political formations, such as the Jan Suraaj party, also introduced a new variable by focusing on mobilising these non-traditional voters.What the surge in turnout implies for BiharThis turnout surge is a central question. In Bihar’s political history, sharp turnout increases have sometimes signaled major shifts in power. The 1990 election, which brought Lalu Prasad to power on the back of the Mandal movement, saw a significant surge in turnout. This suggests a new or previously disengaged electorate mobilising for change. However, this pattern is not absolute. The 2005 election, which ended the RJD’s 15-year rule, occurred on one of the lowest turnouts in modern Bihar’s history (45.8%). That change was driven not by mass participation, but by the strategic realignment of existing caste blocs. The 2025 turnout, therefore, points away from a simple realignment of committed voters and suggests a broader, wave-like mobilisation. The direction of this wave – whether for or against the incumbent – is what the final results will reveal.The quality of the mandate and a new political calculusBihar’s elections have often produced results where a party’s seat share did not match its vote share. The Disproportionality Index (DISP), which measures this gap, can indicate voter disillusionment. The 2020 election had a high DISP of 22.22; both major alliances secured an identical 37.2% vote share, but the NDA formed the government with a 15-seat advantage. Such outcomes can make voters feel the popular will is not reflected.A high voter turnout, as seen in 2025, often results from a clear political wave. The turnout did not rise uniformly, increasing from 65.08% in Phase I to 68.76% in Phase II, suggesting a building momentum. This can lead to larger victory margins. If this occurred, the DISP for the 2025 election would likely be lower than in 2020, meaning the final seat tally more accurately reflects the popular vote.Data noteA discrepancy of 1,70,882 electors – a figure that could be minor or major depending on how close tomorrow’s election results are – exists between two official totals. The first figure (7,43,55,976) is from the final SIR list of September 30 and the ECI’s election announcement on October 6. The second, larger figure (7,45,26,858) is the final certified electorate in the ECI’s post-poll press note.Usually, this is explained as the result of the “continuous updation” of rolls. If that is the case, it means roughly 1.7 lakh voters were added between October 6 and October 10, just 10 days before the final day for filing nominations.However, given the high stakes, last year’s razor-tight election, and the opposition’s allegations of voter manipulation related to the SIR, this number could become a point of contention. The Election Commission will need to clarify this soon.