India, June 14 -- For a leader who rebuilt herself from the ruins of electoral defeat not once but several times-who broke away from the Congress, founded a party from scratch and eventually brought an end to the Left Front's 34-year rule in West Bengal in 2011-the week gone by may well represent the point of no return.

Mamata Banerjee, founder and supreme leader of the Trinamool Congress (TMC), returned from New Delhi earlier this week having achieved little politically, even as her party fractured simultaneously in Parliament and the West Bengal Assembly, civic bodies slipped from its control and investigators searched the party office located within her Kalighat residence. The scale of the crisis is unprecedented in the party's histor...