The biggest crime that West Bengal Chief Minister Mamata Banerjee has committed is to bring the Bharatiya Janata Party to the state riding on her shoulder. The Left Front and the Congress may have become weak, but the people of Bengal will have to oppose both the Trinamool and the BJP if the state has to progress. These are some of the views expressed by the senior leader of the Communist Party of India-Marxist Dr Sujan Chakraborty in an exclusive, free-wheeling interview with Paranjoy Guha Thakurta.