India's communists once ruled millions. What happened to them?

BBC News 

India's communists once ruled millions. For the first time since 1957, India no longer has a single communist-led state government. The defeat of the Communist Party of India (Marxist)-led Left Democratic Front (LDF) in Kerala this month, after a decade in power, marked the end - at least for now - of one of the world's most enduring experiments in democratic communism. At their peak, India's communist parties ruled states stretching from West Bengal to Kerala and Tripura. They impacted the lives of more than 100 million people through trade unions, peasant organisations, student wings and disciplined cadre networks.