(Bloomberg News) U.S. Senate candidate Elizabeth Warren, in a high-profile speech at the Democratic National Convention, intensified her criticism of Wall Street, saying CEOs who wrecked the U.S. economy with risky bets "still strut around Congress" and demand favors from lawmakers.

In a blistering address to delegates in Charlotte, North Carolina and to a national television audience, Warren described a broken government that is stacked against the middle class, to the cheers of a crowd chanting her name.

"People feel like the system is rigged against them," Warren, of Massachusetts, said last night. "And here's the painful part: They're right. The system is rigged. Look around. Oil companies guzzle down billions in profits. Billionaires pay lower tax rates than secretaries."

Warren, who helped President Barack Obama create the Consumer Financial Protection Bureau, drew repeated contrasts between the president and Republicans. Mitt Romney would help billionaires and big corporations and perpetuate the problems that allow companies to have too much influence, she said.

"Republicans say they don't believe in government," she said. "Sure they do. They believe in government to help themselves and their powerful friends."

Some members of the New York delegation cheered at her attack on Wall Street executives.

"I wouldn't call it Wall Street bashing," said Representative Carolyn Maloney of Manhattan. "She bashed people who abused the system. That's not Wall Street. That's individuals."

Lightning Rod

Warren, 63, is a one-time adviser to Obama who is running against Republican incumbent Scott Brown, and her critiques of business have made her a lightning rod for Republicans. The outcome of the race could help determine which party controls the Senate, where Democrats have a 53-47 majority and are defending seats in Republican-leaning states including North Dakota, Nebraska and Missouri.

"She stuck it, it was perfect," John Walsh, chairman of the Massachusetts Democratic Party, said after the speech. He said he expects the race to be close and come down to grassroots campaigning in the final weeks. Warren was the most prominent woman speaker on the second night of the Democrats' convention.

Kennedy's Seat

In a state where Democrats far outnumber Republicans, Warren, a professor at Harvard Law School, is her party's hope to recapture the seat long held by Ted Kennedy, who died in 2009. Criticizing Wall Street and big banks has been her calling card.

"Corporations are not people," Warren said, speaking rhetorically and directly to Romney. "People have hearts, they have kids, they get jobs, they get sick, they cry, they dance."

Warren is the Democratic equivalent of Republican Governor Chris Christie of New Jersey -- someone with the star power and national stature who represents the future of the party, said Michael Goldman. He has consulted on campaigns for Democrats since the 1960s, including for U.S. Representative Thomas P. "Tip" O'Neill, the late House speaker from Massachusetts.

Warren offered Democrats something Christie couldn't for his party -- a personal and professional testimonial about their nominee based on her experience working with him in the trenches, Goldman said.

'Make Things Work'

"Part of the whole idea of the convention is that the president wanted to make things work even with the Republicans blocking his path at every turn, and yet despite that there were successes," Goldman said. "Her speech is about what Barack Obama asked her to do, what she did and the success that they had in helping Americans through the creation of the Consumer Financial Protection Bureau."

Brown, 52, is trying to win re-election by focusing on a bipartisan record in Congress while characterizing Warren as an ideologue who will further polarize politics in Washington.

"Brown is a bridge builder, not a rock thrower," Alleigh Marre, a spokeswoman, told Bloomberg in an Aug. 14 e-mail. "The last thing we need in Washington right now are partisan ideologues like Professor Warren who would rather leave blood and teeth on the floor than compromise."