Donald Trump is railing against Sen. Elizabeth Warren, calling the Massachusetts Democrat "goofy."
Trump tells supporters in Eugene, Oregon, on Friday evening that his likely rival, Hillary Clinton, has "got this goofy friend named Elizabeth Warren."
Trump is calling Warren a "goofus" and a "basket case," and says "she's done nothing in the United States Senate."
Warren had earlier insulted Trump on Twitter, calling him "a bully who has a single play in his playbook."
Trump's Twitter account responded with: "Goofy Elizabeth Warren, Hillary Clinton's flunky, has a career that is totally based on a lie. She is not Native American."
Warren faced questions about her Native American ancestry during her 2012 Senate campaign after being listed as such at Harvard University.