The origins of the surge in claims of Hindu Pride.
All communities who have been humiliated naturally resent that, and are thus highly receptive to the idea of their group-identity 'pride'. Americans have never, as an identity, been humiliated, unlike the Chinese, the Australian Aboriginals, the Germans, or Japanese. Nonetheless, Trumpism in the US is associated with MAGA, which appeals to sections of the American public who feel humiliated, and thus they aggressively promote their pride.
Hindus, as a community, once peopled the wealthiest land on the globe. As a religious identity, they were a mix of the old Indus Valley civilisation and the Arian migration. Modern research has opted to believe there was probably little broad conflict as these two streams merged thousands of years ago, as it happened over a long time. Nonetheless, even today there is a derogatory term which originates between the caste and non-caste, meaning those who could speak Sanskrit and those who couldn't. This is the only vestige of the rivalry between the two top Arian varnas (over-caste) and what are now called sudras. The tribals are another story altogether, but including them here would only complicate this unnecessarily - suffice to know they are extremely important in Indian social history.
The first major humiliation of Vedic Brahmanical religious identity, was when Buddhism swept across India. Hinduism reasserted itself especially from the extraordinary efforts of the long-lived Shankara, who out-debated everyone. Still, the two religions were relative brothers despite the ubiquitous sculptures of the Lion dominating the Elephant through India, when the Islamic invasion destroyed the fabulous wonders of both Hindu and Buddhist temples and centres across North India. (Muslims in South India tended to arrive through trade rather than violent invasion, and are integrated more harmoniously there still today, much to the annoyance of the current ruling central political party).
The third major humiliation was the British conquering of India. This was as humiliating as the Islamic, but where the Muslims from Persia believed themselves to be superior (with some claim to that), they didn't overtly humiliate the Hindus in anywhere the same way as the British, who believed Hindus to be cowards, effeminate, children, and incapable of being civilised - worshipping bloodthirsty evil demons. They humiliated not just the community, but their religion, intelligence, masculinity, art and languages. To cement all that, they consistently defeated them in battle and tricked them whenever it was easier, then subsumed them into their army, administration and business, while murdering countless millions and stripping the land of its wealth. The only Indians who outwitted the British were the wealthy money lenders.
You can understand then, why the concept of Hindu identity pride would find such fertile embrace. It is a transition and evolution of a nation that was waiting to be exploited as soon as some politically savvy operatives could generate traction. What is amazing is how long it took, and how much effort was expended before the Hindutva social and political organisations could rally enough support to win elections. Now, of course, it's taking off like rocket fuel.