Rise of Hindu Nationalism in India after 70 years of Independence, is nothing something unexpected phenomenon, which is sweeping the nation since last two decades.
Its roots lie deep down in Mahatma Gandhi's social, political ideology which couldn't be digested by a large section of believers in Akhand Bharat (Undivided or Greater India) before and after British Rule.
Nothing apart was followed by Gandhi's ideologue Nehru, overlooking deep down tides of dissatisfaction taking shape of Hindu Nationalism.
After 1947 Gandhi's and Nehru's secularism didn't catch up masses that had been under foreign oppression since last 10 centuries, and paved a way to Rashtriya Swavamsewak Sangh jumping into politics.
Hindutva was never seen as an uniting social and political force in modern India until 1906 when Agha Khan founded Muslim League in undivided India.
Even after inception of Rashtriya Swavamsewak Sangh in 1925 by Keshav Baliram Hegdewar, Hindutva had not been a political entity, as Britishers, Gandhi, Nehru did not heed on it as a potential stakeholder.
All Indians had at that time was Congress Party as a secularist for whole India, on the other side was Muslim League for separate Muslims State to negotiate with Britishers.
Gandhi and Nehru talked about Idea of India which we have now, while Muhammad Ali Jinnah produced present day Pakistan, and no one listened to what Hindus wanted.
Since Mughal invasions till British Rule, and from partition of India until late 1970s Hindutva remained a largely neglected and unheard social and political entity.
Nonetheless, until late 1970s and early 80s religion remained out of political agenda of Congress and other left parties, as there was no significant amount of Muslim population (5%) left in divided India. As such Hindutva remained unruffled during this period and unknowingly swallowed silent and gradual process of secularisation among people and right wing parties.
But, after this period (late 1970s and 80s) as Muslim voters again started surging, Congress only major political party then, started their minority appeasement against the will of majority of population. Sensing soundless suppression of majority left RSS and other Hindu leaders emerge gradually up surging.
After rift in Congress party owing to rivalry between Indira Gandhi and Murarji Desai, rise of and fall of JP Narayan movement, and split of Janata Party left a void in opposition politics, which was successfully subsumed by Bhartiya Janata Party (Formerly Jan Sangh).
Meanwhile, after Death of Indira Gandhi, sensing its fading voters’ faith, Congress started politics of minority appeasement. This gave a sudden rise of Hindu Nationalism in late 1980s and early 1990s, with Ayodhya Ram Temple movement gaining momentum, well complimented by Rashtriya Swavamsewak Sangha and other hard core Hindu groups coming blatantly to represent and protect Hindus.
Meanwhile, Bharatiya Janata Party, backed by RSS, en-chased the demolition of Babari Mosque in 1992, to draw national attention, awakening consciousness of Hindus.
Rise of Bharatiya Janata Party, since then has been imbibing Hindu Nationalism, which has become contemporary bone of contention between two communities, which is constantly churning up Communal tension in India.