Decode Karnataka: Cooperative federalism and language connection

The recent tussle between the governor and State government in Karnataka as well as the ongoing deliberations by the 16th Finance Commission, have brought the focus back on the concept of federalism, and the perceived threat to it in non-BJP ruled states. While the discussion is currently centred around fiscal federalism, political federalism and language policy are likely to be addressed as well. What is cooperative federalism and how does language figure in it?