ACTUALLY.. for a while i thought the same thing (that Native Americans get offended by the term 'Indian') but as it turns out.. NOT all of them do
in fact, in Rhode Island theres a particular tribe called the Narragansetts and they refer to themselves as Indians all the time and actually.. just recently with all the shit going on with election season, one of the main issues being debated in this state was a casino that they wanted (the Narragansett Indians) so it went on the ballots (question 1) and with all the billboards and promotions that they run.. they always called it an 'Indian Casino'
{shrugs} honestly.. i call them by both names.. they have never expressed being offended to me
when all else fails.. blame the WHITE MAN

(they pretty much named all of us LoL)
im not exactly thrilled about being referred to as 'Hispanic' when the word actually means 'of/from Spain'.. even Latin(o) sometimes makes me wonder where it all came from.. but i cant front that i use the aforementioned terms to refer to myself and other Brown people a lot of the time