India, June 15 -- Politicians have a way of messaging. Behind every handshake and hug lies a reason. One such warm hug hit the headlines when Congress leader Sonia Gandhi met former chief minister Mamata Banerjee this month. The meeting coincided with a series of exits from the crisis-hit Trinamool Congress (TMC) following its loss of power in West Bengal in May after 15 years.

It was not the first time Gandhi and Banerjee had met warmly. Apparently, Gandhi did not merely comfort the embattled Banerjee, who quit the Congress in 1998 to form the TMC. She pushed for unity, triggering speculation about the breakaway faction's merger with the Congress.

A merger would not only salvage the TMC but also infuse fresh life into the Congress in W...