This Politic piece on caste in America is pretty balanced. But one thing that this “Indian Americans are so casteist” discourse misses is that 85% of Indian American Hindus are “General Category”, with a few percent being Dalits or Scheduled Tribes (the remainder are OBC). There aren’t many low caste people to discriminate against, but secondarily, America is a caste shredder.
The latest surveys suggest that for Indian Americans born in the USA, 30% of their spouses are non-Indian, 30% of their spouses are US-born Indians, and 40% of their spouses are Indian-born Indians. I’m willing to bet that the vast majority of the the 30% who marry other US-born Indians are marrying outside of their jati-varna. I suspect that perhaps a majority of the remaining 40% who have Indian-born Indian spouses are jati-varna endogamous because of arranged marriages, but I know a substantial number of US-born Indian Americans, men and women, who met and married Indian-born Indian immigrants, usually meeting them through work or social contexts. I am pretty sure that the majority of US-born Indians are marrying outside of their jati, often outside of their region.
You can test this proposition at the high socioeconomic status groups by looking at the NY Times Wedding Announcements.
Look under some very distinctive names, and look who they are marrying.