What were socio-political implications of Aryan Invasion Theory? Discuss.

The Aryan Invasion Theory was propounded much before archaeological excavations were carried out in undivided India. Modern scientific tools had shown that the mighty river Saraswati existed and was not a mythical one as had been claimed.
The Theory explains that early settlements in the Indian subcontinent is a myth and genetic diversity found in South Asia is much older than 3,500 years when the Indo-Aryans were supposed to have migrated to India. The Theory, which says that the Aryans defeated “pre-Aryan” original inhabitants of India, has been a controversial theory. As per this theory, the Harappan civilisation declined by 1800 BC and the Aryans appeared in north-west India around 1500 BC.
Since 19th century, many scholars used the philological evidence, the overlap between Vedic Sanskrit, Old Persian and ancient European languages to argue that the Rig Vedic Aryans came from outside.However, the most important socio-political implication of this theory was that it gave the impression that North Indians are outsiders and Dravidians are original inhabitants of India.It also furthered the gap between lower and upper castes in the society and led to lower caste movements since the 19th century in Western and Southern India.