Massachusetts Senator Elizabeth Warren took aim at Donald Trump Monday, writing on social media, “Let’s be honest—Donald Trump is a loser. … Listen to the experts who’ve concluded he’s so bad at business that he might have more money today if he’d put his entire inheritance into an index fund and just left it alone.” Trump struck back by attacking Warren’s past claims she has Native American heritage. In response to a reporter’s question, Trump referred to Warren as “the Indian.”

Reporter: “You heard a little bit about what Hillary Clinton said this morning in her comments to AIPAC. Also, Elizabeth Warren today on social media went after you, calling you a loser. How are you going to”—

Donald Trump: “Who’s that? The Indian? You mean the Indian?”