Most of the violent aspects of caste discrimination occur at lower socioeconomic levels, where the intensity of the tribalism is exacerbated by poverty.
However, many middle class Indians in the US still follow traditional caste rules in aspects of their personal lives, particularly in marriage, and sometimes in other social associations.
There is also some selection bias among many Indian immigrants towards egalitarianism, leaving behind stifling aspects of the old culture.
The horrible acts of discrimination described in the article are a product of both the Indian social structure and the local communal conflicts.
Hence, in places like the US, Indians are more likely to have professional spouses, whether those spouses are Indian or not.
It's more about your education level and how useful you are than who your ancestors were, but that is many times intertwined.
Edit: India, like most places, is in the middle of re-drawing it's caste system along socioeconomic lines. Of course, the lower castes will still be on the bottom and possibly discriminated against due to being behind on resources being passed down to them.
While Indians in the US tend toward the upper castes, it's not true that there aren't any people in the US of lower caste as well. Even in India the disparity between the castes is narrowing as affirmative action and modernization render such differences moot–as such, it isn't really true that people of lower cast have a "lack of resources", so there are people that are able to come over.
Is it offensive to ask this about indians in the US?
As for offensiveness, I don't remember anybody asking me about my caste (outside of govt forms-they need it for job/educational reservations) except once. He (an Indian from my state) didn't ask me my caste, he heard my name and immediately said "oh you are a Nair" and I felt really weird and wanted to end the conversation quickly. If a foreigner asks me, I don't think I would mind. I am not sure if I would be comfortable if an Indian asks me though.
Nair is actually included in my name so you get the caste info just by getting my name.
We never discussed caste. It was a non-issue.
Prime Minister Modi is also Low Caste. That didn't stop him from being elected.
Of course this is being opposed by "community leaders".
Interesting a woman from my home town was recently abused for being low caste. http://www.bbc.co.uk/news/uk-england-38663143
It would be interesting to beak down H1B's by caste