After V P Singh purposefully used Mandal Commission report, identity politics became crucial in various states. If one takes examples of states where Congress has not much role at all, such as Tamil Nadu, one would not fail to see that 'identity' is a major factor. Dravidian or Tamil identity for Tamil Nadu, NTR used Andhra feelings yo garner support, so is TRS in the present day.
With RSS got an upper hand using a bigger identity game in the form of Hindu Swabhiman, Congress lost its foot hold. Now, the Hindu identity politics of the BJP are successfully countered only by the regional parties, using their regional identity markers. But in the long run, chances are that the majoritarian feelings in the form of religious feelings would swallow even regional sentiments.
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