Democratic presidential front runner Hillary Clinton used a term offensive to Native Americans in her description of Donald Trump.
On Friday, Clinton describe the Republican front runner as being "off the reservation" with his comments against her.
"I have a lot of experience dealing with men who sometimes get off the reservation in the way they behave and how they speak," Clinton said on CNN's "The Lead" with Jake Tapper.
The Bernie Sanders campaign called Clinton's choice of words "disappointing."
"I find it very disappointing. Anyone with a true understanding of the fundamental issues facing tribal communities today would never use that phrase in that context," Nicole Willis (Confederated Tribes of Umatilla), Sanders's National Tribal Outreach Director, wrote in message to ICTMN on Friday.
The derivation of the offensive term comes from the 19th century when the U.S. confined Native Americans to prison camps, today known as reservations. The phrase was used to identify "hostile" Native Americans who were found outside of reservation boundaries.
Tapper later agreed during an interview with professor and pundit Nina Turner that the term Clinton used is highly offensive.
The Clinton campaign has not responded to ICTMN's request for comment.
Watch the interview here: