Sen. Elizabeth WarrenElizabeth Ann WarrenDNA is irrelevant — Elizabeth Warren is simply not Cherokee The Hill's 12:30 Report — Trump seizes on immigrant 'caravan' for midterms | WHCA criticizes Trump for praising lawmaker who assaulted reporter | Trump takes harder line on Saudis Clinton aide: Chances 'highly unlikely' but 'not zero' Hillary will run for president again MORE (D-Mass.) on late Wednesday urged all Americans to unite against GOP presidential front-runner Donald TrumpDonald John TrumpCorker: US must determine responsibility in Saudi journalist's death Five takeaways from testy Heller-Rosen debate in Nevada Dem senator calls for US action after 'preposterous' Saudi explanation MORE.

“I take Donald Trump very seriously,” she told host Chris Hayes on MSNBC’s “All In." "What he is promoting is a form of hate that is virulent and that is bad for our country.

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"It is time for all of us to speak out — Republicans, Democrats, independents, libertarians, vegetarians — everybody, to say no to the Donald," she added.

“We cannot have a man like this as a serious candidate for president and have him threaten to take over the White House. This is not a reality show. This is real life, and this is our country.”

Warren argued that Trump is the latest manifestation of GOP extremism, citing Republican opposition to confirming Supreme Court nominee Merrick Garland as another example.

“Let’s face it, Trump is a natural consequence of that,” she said. "I think all these pieces are weaving together, and they fall at this high point now — or this low point.

“With Trump as the presidential nominee, and Senate Republicans having picked this position that says, ‘We’re not going to hold hearings and vote on a vacancy in the United States Supreme Court basically for a year,’ this is really pretty stunning."