Indio is derived from the term Indigenous or Indian. It's mainly used to describe someone of mostly mesoamerican (Mexican or South American) decedent. However, it's a pun ...
In some late Latin (Roman) dialects it sounds like "by god". And that's correct, It was the Roman Catholic Church who included those people. The people from Iberia Hispania (Spain and Portugal) are the Latinos. They were granted Latin rites by an Emperor and may not a full blood line link to Latium.
Southern Italians are the true Latins, they are Latini.
He's not sanguinis, he's a mexican indio