Elizabeth Warren is taking her war with Donald Trump to a new level, and it goes well beyond her usual 140-character Twitter attacks on the likely GOP presidential nominee.

The Massachusetts senator on Tuesday night dedicated a speech to rallying opposition against Trump — calling him a "small, insecure moneygrubber" who she said is "kissing the fannies of poor, misunderstood Wall Street bankers."


"He inherited a fortune from his father, and kept it going by scamming people, declaring bankruptcy and skipping out on what he owed," Warren said in prepared remarks, calling into question Trump's bona fides as a populist champion.

The assaults on Trump are becoming Warren's signature contribution to the Democratic Party's attempt to retake the White House. The speech was the second time Tuesday that she stepped into the national political fray, a sign that she's becoming increasingly vocal in the presidential race, positioning herself as a power player for the progressive left. Warren is expected to play a big role in uniting the party after the presidential primary.

She has continued to hold back an endorsement of the party's likely nominee, Hillary Clinton, who is struggling to win support from liberals aligned with Warren and Sen. Bernie Sanders. Earlier in the day, Warren helped a coalition of labor and public interest groups kick off a major campaign aimed at cracking down on Wall Street in ways that would be more aggressive than what Clinton has proposed. Focusing fire on Trump has been a convenient way to help the party without praising Clinton and her policies.

The speech marked an escalation in the fight that Warren and Trump have been waging over social media since it became clear that the real estate developer and reality TV star had a clear path to the Republican nomination. Trump has called her "goofy" and has tried to revive controversy from her 2012 Senate campaign related to what she has said is her Native American heritage.

Speaking to a Washington gala hosted by the Center for Popular Democracy, Warren called into question whether Trump is looking out for the best interests of economically downtrodden voters that he has claimed to champion. She tried to link him with the powerful corporate interest she has spent so much time vilifying: Wall Street.

Warren cited Trump's comments that he is planning to dismantle the 2010 Dodd-Frank law that overhauled the regulation of banks and markets in the wake of the 2008 financial crisis. She questioned whether he can "even name three things" the law accomplished.

"Now that he's sewn up the Republican nomination, Donald Trump is dropping the pretense" of being tough on Wall Street, Warren said. "Now he's kissing the fannies of poor, misunderstood Wall Street bankers. But the American people are not looking for a bait and switch."

Warren suggested Trump is not releasing his tax returns because he is a "lousy businessman who doesn't want you to find out that he's worth a lot less money than he claims." She cited Trump's 2007 comment that he was "excited" about the prospect of making money during the real estate market crash.

"What kind of a man does that?" she said. "I’ll tell you exactly what kind — a man who cares about no one but himself. A small, insecure moneygrubber who doesn’t care who gets hurt, so long as he makes some money off it. What kind of man does that? A man who will never be president of the United States."

As Warren focuses fire on Trump, she is keeping pressure on the Democratic Party to take a tougher line with the banking industry.

Earlier in the day, she gave a speech to a roomful of her allies at an event kicking off a "Take On Wall Street" campaign backed by labor and public interest groups — including officials who are on opposing sides of the Clinton-Sanders primary fight.

A goal of the campaign is to drum up support for reining in the finance industry, including reinstating Depression-era restrictions on banks — a signature policy of Warren and Sanders, but one that Clinton has declined to adopt.

The campaign is the latest sign that many in the Democratic Party want to go beyond the former secretary of state’s more nuanced approach to policing the financial system and that it could remain a source of tension with progressives.

To be sure, the campaign's agenda overlaps with Clinton's Wall Street platform. Both are calling for taxes on financial transactions. They both want to close the carried interest tax loophole that benefits private equity and hedge fund managers.

"From the standpoint of [Clinton's] campaign, if I was going to offer advice, I would keep listening and ... really try to soak in how very upset people are" about Wall Street greed, Rep. Keith Ellison (D-Minn.), a Sanders backer, said in an interview after speaking at the event.

In the view of Warren and AFL-CIO President Richard Trumka, who also spoke at the "Take On Wall Street" launch, Dodd-Frank was only the beginning.

Trumka, who has not endorsed a presidential candidate, said too many decisions have been left in the hands of the regulators and that a "bigger and bolder approach" is needed.

"We are in this fight because someone has to be willing to fight back, and that's us," Warren said. "If we fight shoulder to shoulder, we will win."