177. Thiruthuraipundi

Communist Party of India held the seat; the winning margin narrowed from 28.7% to 19.4%.

Boundaries were redrawn between 1971 and 1977 — the comparison is matched by name and is indicative only.

• Won on a lower shareIts own vote share fell 16.9% — it held because the rest of the vote was more divided.
• New challengerDravida Munnetra Kazhagam (DMK) finished second with 26.5% — it did not contest here in 1971.
• Vote fragmentedThe top two took only 72.4% between them, down from 97.0% — the field split more ways.

Written from the constituency figures by a fixed set of rules — no language model.