Regionalism can be defined as “a phenomenon in which people’s political loyalties become focused upon a region, often in preference to the country or state of which the region is a part”. In India, regionalism is rooted in geographical, historical, socio-economic and politico- administrative bases. India’s diversity of languages, culture, tribal identity, caste and religion and the geographical concentration of these markers of identity in particular regions is often fuelled by a sense of regional deprivation. Resultantly, regionalism has manifested itself in various forms in the post independence period:

• Separatism & Secessionism: This form of regionalism emerged in the form of demands of people in certain states or regions to secede from the Indian Union and become independent sovereign states. The important examples in this context are that of the Plebiscite Front (Kashmir), Khalistan Movement in Punjab, Mizo National Front (Lushai Hills of Assam), Nagaland Socialist Conference (Naga Hills District of Assam) etc.
• Supra-state Regionalism: It is an expression of group identity of some states; wherein they take a common stand on the issues of mutual interest vis-a-vis another group of states. The group identity is usually in relation to certain specific issues. For example, the rivalry existing between south and north India on such issues as language illustrates the point.
• Inter-state Regionalism: It is related with state boundaries and involves overlapping of one or more state identities, which threaten their interests. River water disputes, in general, and other issues like the Maharashtra-Karnataka border dispute in particular can be cited as examples.
• Intra-State Regional Politics or Sub-Regionalism: It embodies the desire of a part of a state for identity and self-development. It may also reflect a notion of deprivation or exploitation of a part of the state at the expense of another. The important examples of this kind of sub- regionalism are bifurcation of Andhra Pradesh, concerns of people of Vidarbha in Maharashtra; Saurashtra in Gujarat; Eastern U.P. etc.
• Sons of Soil theory: This theory ties people to their place of birth and confers some benefits, rights, roles and responsibilities on them, which may not apply to others. It is accentuated by factors like resource competition, employment opportunities, economic disparities, etc. Also, there might be a feeling of one being superior to others in culture, language etc. Examples of implementation of the concept to further the cause of regionalism include campaign for safeguard of interests of Maharashtrians by the Shiv Sena etc.

Regionalism is the desire to concretise regional identities. if a federal polity provides enough space for the expression of the same, regionalist tendencies can be channelled to spur development both in the region and the nation. Hence, regionalism must not be viewed only as a threat to national identity. In fact, efforts must be made to reconcile competing claims of regionalism and national integration.