By Amanda Becker
CINCINNATI (Reuters) - Liberal Elizabeth Warren attacked Republican Donald Trump on Monday during her first campaign appearance with U.S. Democratic presidential candidate Hillary Clinton, calling him an "insecure money grubber" who is driven by greed and hate.
Warren, a leader of the Democratic Party's progressive wing and a potential vice presidential pick, said Clinton had spent her career fighting for liberal values while Trump, a wealthy real estate developer, was focused on boosting his bottom line.
The U.S. senator from Massachusetts appeared with Clinton before a raucous, enthusiastic crowd in Cincinnati, Ohio, targeting a battleground state in a potential preview of a Clinton-Warren campaign team. She repeatedly accused Trump of looking out for himself instead of for average Americans.
"When Donald Trump says he'll make America great, he means make it even greater for rich guys just like Donald Trump," Warren said, standing shoulder to shoulder with a cheering Clinton.
Clinton has struggled to win over some liberal backers of rival Bernie Sanders, a democratic socialist U.S. senator from Vermont, since beating him for the Democratic nomination this month. She hopes the support of Warren can help her in that effort as she campaigns against Trump for the Nov. 8 election.
Warren, who has vigorously attacked Trump in recent weeks, called him "a small, insecure money grubber who fights for no one but himself" and warned: "He will crush you into the dirt to get whatever he wants. That's who he is."
The capacity crowd repeatedly roared its approval, and a line of supporters who could not get inside stretched out the door and down the street. At one point, Warren stopped her speech to turn and applaud Clinton, a former secretary of state.
"She knows what it takes to beat a thin-skinned bully who is driven by greed and hate," said Warren, known for calling for reining in Wall Street and eradicating income inequality.
WARREN 'A SELLOUT' - TRUMP
In a statement, Trump called Warren "a sellout" for backing Clinton, who has taken donations from Wall Street interests and once backed the Trans-Pacific Partnership, the Asian trade deal. Clinton has since reversed her trade stance.
In an interview with NBC News, Trump called Warren "a fraud" and "a racist," accusing her of making up claims about her Native American heritage to advance her career.
He again called Warren "Pocahontas," the name of a 17th-century Native American figure, to draw attention to a controversy first raised during Warren's 2012 Senate race in Massachusetts.
"She is one of the least productive senators in the United States Senate," Trump told NBC. "We call her Pocahontas for a reason."
Two other potential Clinton vice presidential picks - U.S. senators Tim Kaine of Virginia and Sherrod Brown of Ohio - rejected Trump's assertion and defended Warren's record.
"That’s what he does, he attacks people. He acts like he’s attacking their character - he’s attacking his own character when he does that," Brown told Reuters.
“You can’t believe anything Donald Trump says. Period," Kaine told Reuters.
Taking the microphone in Ohio, Clinton said she liked Warren's aggressive approach to her Republican rival, who has sprayed rivals and critics with insults throughout his campaign.
"I just love how she gets under Donald Trump's skin," Clinton said.
Clinton's decision to campaign with Warren for the first time in Cincinnati, a city on Ohio's southwestern border with Kentucky and Indiana, underscored the swing state's vital role in the November showdown with Trump.
Ohio has backed every successful presidential nominee since 1964 and no Republican has won the White House without carrying the state.
Warren's calls to rein in corporate excess could resonate with two groups Clinton must court in the election - Sanders supporters and those anxious about the economy who are drawn to Trump's promise to toss out international trade deals.
Ohio's manufacturing base has taken a hit in recent economic slowdowns, and Trump has identified it as a state where his anti-free trade rhetoric could resonate with alienated blue-collar voters.
Since becoming the presumptive Democratic nominee, Clinton has repeatedly tried to portray businessman Trump as fundamentally unfit for the presidency. Clinton said Warren's long history of fighting for progressive economic values made her a perfect messenger for that critique.
(Writing by John Whitesides; additional reporting by Susan Cornwell; Editing by Frances Kerry and Howard Goller)