Hindu nationalism has the most support from Upper castes. The majority of Hindus in the west anyway support RSS and in the west they become champions of minority rights and anti-discrimination. A majority of Indians who come to the west are also mostly Upper castes because unlike the gulf which give the job to all strata of people, only high profile people are given visas which happen to be high castes because generationally they hold the majority of the country wealth. So how is your statement many Indians who come to the US care about caste due to reservation even make sense?