Why did Mayawati blink? That’s the question everyone is asking about the BSP chief who seldom gives in. No one can answer right now, but another BJP ally, Mamata Banerjee, offered some clues in Lok Sabha today though the discussion had nothing to do with UP.Participating in the discussion on a Bill to legitimise contributions to political parties, Mamata spoke with great feeling about difficulties faced by ‘‘small parties’’ in fighting elections. She said parties which ‘‘are not in power’’ find it impossible to meet election expenses.Although Banerjee’s target was CPI(M) in West Bengal, the message was clear. One sure way of making money to fund elections came from being in power. Contributions were easier to come by for a party in power, and so were chances to make money via kickbacks.Mamata did not refer to the money-making abilities of any NDA ally, of course. She trained her guns at CPI(M), which she said had no money before it came to power but now indulged in ‘‘10-star hotel’’ culture. Demanding an investigation into political funds, she told CPI(M) MPs: ‘‘Then your cat will be out of the bag first.’’ It was left to a Congress MP to point out that if CPI(M) was making money by running a state, NDA must be making more. Offended at the insinuation that she was allying with NDA for pecuniary reasons, she thundered: ‘‘We are supporting BJP as it is our ideological support, it is our moral support — we are not purchasable commodity.’’