India, April 26 -- The longest absence is the most definitive marker. In Tamil Nadu, the Indian National Congress last held the chief minister's office in 1967, when M. Bhakthavatsalam demitted power. Nearly six decades on, the party remains structurally excluded from a Dravidian system it once dominated. That long arc now faces a live electoral test, with five states, Tamil Nadu, West Bengal, Kerala, Assam and Puducherry, in the middle of an election cycle that mirrors the geography of its decline.

decade later. West Bengal has not seen a Congress chief minister since 1977, when Siddhartha Shankar Ray exited office, giving way to a prolonged Left Front rule and later to the All India Trinamool Congress. In Tripura, the last Congress chi...