BOSTON - Massachusetts U.S. Senate candidate and former White House adviser Elizabeth Warren came out swinging tonight against Mitt Romney in a fiery address to 1,800 Obama campaign donors at Symphony Hall.

"It's clear where President Obama stands and it's just as clear where Mitt Romney stands," a steely Warren told the crowd.

"No, Mitt, corporations are not people," she deadpanned, referencing Romney's comment from the Iowa State Fairgrounds last summer, when he explained "corporations are people, too."

"People have hearts. They have kids. They get jobs. They get sick. They love and they cry and they dance. They live and they die," she said. "Learn the difference."

The crowd burst into thunderous applause.

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"And Mitt, learn this," Warren added. "We don't run this country for corporations. We run it for people."

Warren, who employed her trademark impassioned, populist rhetoric, hailed President Obama has a defender of the middle class who had achieved important consumer protections in spite of aggressive Republican opposition.

"Big banks and Republicans fought tooth and nail against us. They vowed this agency [Consumer Financial Protection Bureau] would never become law. … When the money poured in and the pressure mounted against us and we were on the ropes, President Obama stood firm.

"We know where president Obama stands," she said. "President Obama stands for working people."

Warren introduced Obama, who then delivered his second address to donors of the day, his 99th fundraiser of the year.