India, April 22 -- The Tamil Nadu assembly election is significant in multiple ways. One, it is a test for the DMK, the incumbent, which has never won back-to-back assembly polls. The DMK-led Secular Progressive Alliance (SPA) is a mega socio-political coalition that includes the Congress, Communist parties, Dalit and minority voices, among others, but it faces a demanding electorate. The SPA near-swept the general elections in 2024, but assembly polls have their own logic, shaped by local factors.

Two, Tamil Nadu politics, though largely a DMK-AIADMK duopoly, has been unravelling in the past few years. With over 8% vote in its debut election in 2006, the DMDK challenged the duopoly but couldn't sustain the momentum and fizzled out. This...