Finding — Where the seats flipped: the 2021 → 2026 party transfer matrix ​
DMK held only 40 of its 2021 winning seats. 65 went to TVK, 22 to AIADMK. AIADMK held only 22 of 66. Two-thirds of all sitting MLAs lost their seats.
The full flip matrix ​
| 2021 winner | 2026 winner | Seats flipped |
|---|---|---|
| DMK | TVK | 65 |
| AIADMK | TVK | 26 |
| DMK | AIADMK | 22 |
| AIADMK | DMK | 15 |
| INC | TVK | 11 |
| BJP | TVK | 2 |
| BJP | DMK | 2 |
| PMK | TVK | 2 |
| DMK | PMK | 3 |
| PMK | AIADMK | 2 |
Held seats by party ​
| 2021 winner | Held in 2026 | 2021 total wins | Retention % |
|---|---|---|---|
| DMK | 40 | 133 | 30% |
| AIADMK | 22 | 66 | 33% |
| INC | 4 | 18 | 22% |
| CPI | 2 | 2 | 100% |
| PMK | 1 | 5 | 20% |
| VCK | 1 | 4 | 25% |
Massive incumbency turnover
Two-thirds of TN's 2021 sitting MLAs lost in 2026. Only ~70 of ~234 sitting MLAs retained their seats. This is by far the largest mid-state-cycle MLA turnover TN has seen in living memory.
The headline flow: DMK → TVK (65 seats) ​
This single flow accounts for the majority of TVK's 108 wins. 65 of the 234 ACs (28%) saw their 2021 DMK MLA replaced by a 2026 TVK MLA. In a typical 5-year election cycle, anti-incumbency churn is 30-50 seats. TN 2026 had ~150 net flips — anti-incumbency at unprecedented scale.
AIADMK → TVK (26 seats) ​
The second flow. AIADMK was already in opposition in 2021, so this isn't anti-incumbency in the usual sense — it's vote consolidation. The seats AIADMK held going into 2026 split: 22 retained, 26 lost to TVK, 15 lost to DMK, and a few smaller transfers.
DMK ↔ AIADMK (22 + 15 = 37 swaps) ​
In the seats where the TVK wave was weakest (Cauvery delta, Vanniyar belt, Thevar belt — see tvk-loss-map), 37 seats swapped between the two old Dravidian majors. This is the "background incumbency-churn" pattern that would happen even without TVK.
INC → TVK (11) ​
DMK's largest alliance partner, INC won 18 in 2021 but only 5 in 2026. 11 of those 13 lost seats went directly to TVK. Lokniti-style analysis would tell us whether INC voters switched to TVK or whether DMK's overall front collapse dragged INC with it.
Smaller-party retention rates ​
- CPI: 100% — held both wins. Smallest possible sample but real.
- CPI(M): held 2 of 2 (similar).
- VCK: held 1 of 4 — DMK alliance partner, Dalit-rights party. The new VCK gains in close races (e.g., AC 72 Tindivanam by 734 votes) are notable.
What's surprising ​
- PMK held 1 of 5 — Vanniyar caste-bloc party in NDA alliance. They retained only 1 seat despite the Vanniyar belt resisting TVK. The Vanniyar bloc voted AIADMK or BJP under NDA arithmetic in 2026, not PMK directly.
- BJP lost 4 of 4 — gained none from their 2021 wins — went from 4 seats to 1, but the 1 they won wasn't one of their original 4.
- TVK had 0 seats in 2021 → 108 in 2026 — the most dramatic single-cycle entry by any party in TN history.
Cross-check ​
- Source: 2021 winners from
s3://tnelection2026/historical/curated/year=2021/kracekumar_detailed.parquet. 2026 winners froms3://tnelection2026/results/curated/year=2026/.../candidate_totals.parquet. - Flip matrix: inner-join on
ac_no, group by (winner_party_21, winner_party_26). - Code:
pipelines/mega_insights.py(S14 section).