EUGENE, Ore. — Donald Trump put Sen. Elizabeth Warren squarely in his crosshairs during a campaign rally in Oregon Friday, attacking the progressive firebrand while dismissing her claims to Native American heritage.

The real estate mogul repeatedly called the Massachusetts senator a “goofus” and a “basket case" during a speech to thousands of supporters here, mocking her record in the Senate. He also referenced scrutiny over Warren’s claim that she is Native American, which became an issue during her 2012 U.S. Senate run in the Bay State.

"Her whole career is a fraud because she goes out and she says she's a Native American. I won't use the word Indian because they say it's not a nice word to use. So I will not say Indian,” he told the crowd. “She is a Native American, five percent. And therefore her whole career because she was a minority — it's a disgrace what's going on in our country.”

Warren has emerged as one of Trump’s most aggressive critics, frequently blasting his brand of politics in recent months and vowing to fight to prevent him from winning the White House in November. On Tuesday night she attacked Trump in a series of tweets shortly after he seized his party’s presidential nomination.

“Here’s what else is real: @realDonaldTrump has built his campaign on racism, sexism, and xenophobia,” Warren tweeted in one instance.

“There’s more enthusiasm for [Trump] among leaders of the KKK than leaders of the political party he now controls,” she wrote in another, referencing the hand-wringing within the GOP establishment over Trump’s candidacy.

Trump responded Friday in a series of tweets before taking continuing his attacks on stage in the evening. He later mocked rumors that she may be a potential vice presidential running mate for Democratic presidential front runner Hillary Clinton.

“I think that Hillary should run with goofy Elizabeth Warren. I would love to beat them. I would love to beat them,” Trump said. “They're doing the whole, she plays her woman's card. ... It's the only card she has because honestly without that card she would get nobody voting for her.”

Warren responded Friday with her own series of tweets excoriating Trump.