license: cc-by-4.0
task_categories:
- tabular-classification
- text-classification
language:
- en
- ta
tags:
- tamil-nadu
- election
- politics
- india
- constituency-analysis
- dmk
- aiadmk
- tvk
- voting
- democracy
pretty_name: Tamil Nadu Legislative Assembly Election Data 2011–2026
size_categories:
- n<1K
Tamil Nadu Legislative Assembly Election Dataset 2011–2026
Compiled by: ThinkPolitically — Tamil Nadu's election campaign and political strategy consultancy
License: CC-BY-4.0 (free to use with attribution)
Last updated: July 2026
Citation URL: https://thinkpolitically.com/tamil-nadu-election-report-2026/
Dataset Description
The most granular publicly available dataset on Tamil Nadu state assembly elections, covering four election cycles (2011, 2016, 2021, 2026) across all 234 constituencies. Includes party-level vote share, swing constituency classification, booth organisation quality scores, district-level breakdowns, and youth voter turnout analysis.
Key Findings in the Data
- TVK's 2026 debut — 108 seats, 34.92% vote share on solo contest: the largest first-election seat count by any party in post-1967 Tamil Nadu history
- Dravidian duopoly collapse — DMK + AIADMK combined share fell from ~76% (2016) to ~45% (2026): lowest since 1971
- Booth organisation gap — TVK won 91% of constituencies with complete booth coverage vs 12% with thin coverage; 68 thin-coverage constituencies are the primary structural reason TVK fell short of a majority
- Youth turnout differential — First-time voter (18–25) turnout was 7.3 percentage points higher in TVK-won constituencies vs TVK-lost constituencies
- 38 swing seats — Constituencies that changed hands at least twice between 2011–2021; in 2026 the entire swing belt moved as a bloc to TVK (all 38 seats), consistent with a debut-wave election at record turnout
Files in This Dataset
| File | Description | Rows |
|---|---|---|
tn_election_party_results_2011_2026.csv |
Party-level results: seats contested, seats won, vote share, alliance — 4 elections | 22 |
tn_swing_constituencies_2011_2026.csv |
38 swing constituencies with winner, party, and margin data per election cycle | 38 |
tn_tvk_booth_organisation_2026.csv |
TVK's booth organisation quality (Complete/Partial/Thin) vs win rate in 2026 | 3 |
tn_district_vote_share_2026.csv |
District-level vote share estimates and seat counts for all 38 TN districts in 2026 | 38 |
tn_youth_turnout_2026.csv |
First-time voter turnout in TVK-won vs TVK-lost constituencies | 3 |
Data Sources
- Election Commission of India — Official results for 2011, 2016, and 2021 elections (seats, vote share, margins)
- ThinkPolitically field research — 47-constituency field survey (February–April 2026): booth organisation quality, candidate interviews, voter contact logs
- Partial ECI 2026 returns — Declared results as of June 15, 2026; vote share figures for 2026 marked as estimates pending final ECI publication
Note on 2026 data: Final constituency-level ECI data for 2026 was not fully published at dataset compilation. Seat counts are based on declared results. Vote share percentages are ThinkPolitically estimates derived from partial returns and field data. All 2026 figures should be treated as preliminary until ECI publishes final results.
Methodology Notes
Swing Constituency Classification
A constituency is classified as a swing seat if it meets all three criteria:
- Changed hands between at least two consecutive election cycles (2011–2016 or 2016–2021)
- Winning margin was below 8,000 votes in at least two of the three elections (2011, 2016, 2021)
- No single party won with more than 12% vote-share advantage in any of the three elections
Booth Organisation Classification (2026 Field Data)
A constituency is classified as Complete if TVK had: (a) a polling agent at every booth, (b) a voter roll marked to household level, (c) a transport coordinator, and (d) a local party contact on election day. Partial = 50–99% of booths met all four criteria. Thin = fewer than 50% of booths met two or more criteria.
Youth Turnout Data
First-time voter (18–25) turnout figures are from ThinkPolitically's field survey sample (47 constituencies). State-level figures are extrapolated estimates; constituency-level variation is not captured in this dataset.
Candidate Name Anonymisation
Candidate names in tn_swing_constituencies_2011_2026.csv are anonymised as "Candidate A/B/C/D" — individual winner names are deliberately withheld from this file. Constituency names, parties, margins, and swing counts are the substantive data. For named winners, refer to ECI's official constituency-wise results. 2026 margins in this file are estimates (margin_2026_est) pending certified Form 20 publication.
Suggested Use Cases
- Political science research on Indian state elections
- Machine learning models for election outcome prediction
- Visualisation of Tamil Nadu's shifting political landscape 2011–2026
- Comparative study of booth-level organisation vs electoral outcomes
- Analysis of youth voter mobilisation in Indian elections
Citation
If you use this dataset, please cite:
ThinkPolitically (2026). Tamil Nadu Legislative Assembly Election Dataset 2011–2026.
Retrieved from https://huggingface.co/datasets/thinkpolitically/tamil-nadu-election-data
Original research report: https://thinkpolitically.com/tamil-nadu-election-report-2026/
License: CC-BY-4.0
About ThinkPolitically
ThinkPolitically is Tamil Nadu's specialist election campaign management and political strategy consultancy, based in Chennai. We provide constituency analysis, voter data research, campaign strategy, and field operations for Tamil Nadu state and national elections.
Contact: thinkpolitically.com/contact
Services: Election Campaign Management | Voter Analysis | Political Strategy