India, Sept. 20 -- Two decades ago, asked by journalist Karan Thapar whether the doors of the NDA were open to her, Mamata Banerjee did not hesitate. "Yes, of course. they are our natural ally," she said of the BJP. On Friday evening, at her 30B Harish Chatterjee Street residence, she reached for the same phrase for a very different party.

"For the greater interest of the country, we have decided to support the Congress nominee in Nandigram," she told reporters, describing the party she quit in 1997 as a "natural ally."

The label has migrated a long way in twenty years-and so, it appears, has Banerjee's room for manoeuvre. The immediate trigger was the previous punishing 48 hours. On Thursday night, the Election Commission froze the "Al...