President Donald Trump is not exactly known for racial sensitivity. But he took his ignorance to new heights on Monday, November 27th, when he referred to Senator Elizabeth Warren as “Pocahontas” during an event for Navajo Code Talkers.

The event honored World War II veterans who helped the Marine Corps develop a secret code. Trump addressed three Code Talkers in front of a painting of Andrew Jackson — the president responsible for the displacement and death of many Native Americans through the Trail of Tears.

Trump has used the nickname “Pocahontas” to mock Warren before. He began using the nickname during the 2016 presidential campaign in reference to Warren’s unverified claim that she has Native American ancestry.

Warren responded to Trump’s comments with outrage.

Native American leaders were dismayed and insulted by Trump’s use of “Pocahontas.” Jacqueline Pata, the executive director of the National Congress of American Indians, told The New York Timesthat the remark undercut the honoring of Navajo veterans.

From the cultural appropriation of headdresses to the representation of Native Americans in the media, Native Americans face daily discrimination in modern America. Using the nickname “Pocahontas” as a way to insult and undercut a political opponent only serves to reinforce the problem and sets a terrible example for others.

We can only hope that Trump hears the responses from Pata and other Native leaders and chooses his words more carefully the next time around.