In his 2015 book, Key Concepts in Politics and International Relations, Andrew Heywood wrote:
All forms of identity politics nevertheless exhibit two characteristic beliefs. First, group marginalization is understood not merely as a legal, political or social phenomenon, but is, rather, a cultural phenomenon. Second, subordination can be challenged by reshaping identity to give the group concerned a sense of (usually publicly proclaimed) pride and self-respect – ‘black is beautiful’, ‘gay pride’ and so on.
While identity politics can be traced back to the emergence of the black consciousness movement in the early decades of the twentieth century, it has had its greatest impact since the 1970s. The upsurge in identity politics occurred in the light of growing attacks on liberal universalism, as greater emphasis was placed on the issues of difference and diversity, and the decline of socialism , which, until the 1970s, had been the dominant means through which the interests of subordinate groups had been expressed. The potency of identity politics derives from its capacity to expose and challenge the deeper processes through which group marginalization and subordination take place. As such, it goes beyond conventional approaches to social advancement, based on the politics of rights (liberalism) and the politics of redistribution (social democracy), and instead offers a politics of recognition, based on an assertion of group solidarity.