Donald Trump escalates attacks on Elizabeth Warren: She's a 'racist'

Donald Trump escalated his rhetoric against Elizabeth Warren on Monday, accusing the Massachusetts senator of being a "racist" while reviving his use of the "Pocahontas" nickname.

"She said she's 5% Native American," Trump said in an interview with NBC News. "She was unable to prove it. She used the fact the she was Native American to advance her career."

Scott Brown, a Trump supporter who was Warren's opponent during her 2012 Senate bid, accused her of using her Native American ancestry to her advantage after reports surfaced that she listed herself as a minority in a years-old directory of law professors.

"Elizabeth Warren is a total fraud," he added. "I know it. Other people who work with her know it. Elizabeth Warren is a total fraud. She made up her heritage, which I think is racist. I think she's a racist, actually because what she did was very racist."

Trump said he hoped presumptive Democratic nominee Hillary Clinton selects Warren as her running mate.

"I will speak very openly about her if she is," Trump said. "She is one of the least productive senators in the United States Senate. We call her Pocahontas for a reason."

Trump's revival of the "Pocahontas" moniker comes just days after he claimed to regret using the nickname to describe Warren because "it's a tremendous insult to Pocahontas."

During an appearance on Fox News last Monday, Trump gave a half-hearted apology.

"I do regret calling her Pocahontas, because I think it's a tremendous insult to Pocahontas," he told Fox News host Bill O'Reilly on "The O'Reilly Factor" that night. "So, to Pocahontas, I would like to apologize to you."

Warren appeared on the trail with Clinton in Cincinnati, Ohio, on Monday and called Trump "goofy," another insult the bombastic billionaire has launched her way in recent months.

"Now Donald Trump says he'll make America great again," she said while introducing Clinton at the rally. "It's right there, it's stamped on the front of his goofy hat. You want to see goofy? Look at him in that hat."

"But when Donald Trump says, 'Great,' I ask, 'Great for who, exactly?'" she continued. "For millions of kids struggling to pay for an education? For millions of seniors barely surviving on Social Security? For families that don't fly to Scotland to play golf? When Donald Trump says he'll make America great, he means make it even greater for rich guys just like Donald Trump."

She also called him "a small, insecure money-grubber" and "a nasty man who will never become president."