During the GOP primary, Mitt Romney said that public concern about income inequality and Wall Street excess amounted to “envy” and “class warfare.” The not-so-subtle theme of the RNC was that Obama and the Democrats resented “success.”

Tonight Elizabeth Warren offered a powerful defense of economic populism and a stinging rejoinder to Romney & Co. Here’s a key section from her remarks:

People feel like the system is rigged against them. 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 their secretaries. And Wall Street CEOs—the same ones who wrecked our economy and destroyed millions of jobs—still strut around Congress, no shame, demanding favors and acting like we should thank them.

Does anyone here have a problem with that? Well, I do too. I talk to small-business owners all across Massachusetts. And not one of them—not one—made big bucks from the risky Wall Street bets that brought down our economy. I talk to nurses and programmers, salespeople and firefighters—people who bust their tails every day. And not one of them—not one—stashes their money in the Cayman Islands to avoid paying their fair share of taxes.

These folks don’t resent that someone else makes more money. We’re Americans. We celebrate success. We just don’t want the game to be rigged.

No one, according to Warren, represents the “rigged game” better than Romney.

And Mitt Romney? He wants to give tax cuts to millionaires and billionaires. But for middle-class families who are hanging on by their fingernails? His plans will hammer them with a new tax hike of up to $2,000 dollars. Mitt Romney wants to give billions in breaks to big corporations—but he and Paul Ryan would pulverize financial reform, voucher-ize Medicare and vaporize Obamacare.

The Republican vision is clear: “I’ve got mine, the rest of you are on your own.” Republicans say they don’t believe in government. Sure they do. They believe in government to help themselves and their powerful friends. After all, Mitt Romney’s the guy who said corporations are people.

No, Governor Romney, corporations are not people. People have hearts, they have kids, they get jobs, they get sick, they cry, they dance. They live, they love and they die. And that matters. That matters. That matters because we don’t run this country for corporations, we run it for people. And that’s why we need Barack Obama.

Warren wasn’t always a favorite in Obama’s inner circle—after all, the Obama administration bent to the bank lobby and declined to name her permanent director of the Consumer Financial Protection Bureau she created. But Obama’s campaign theme of economic fairness has been influenced by Warren as much as anybody else. If she has her way, the campaign really will be a contrast of two drastically different economic philosophies. Democrats stumbled in 2010 by seeming as if they prioritized Wall Street over Main Street. Romney gives them a perfect opportunity to correct that wrong. Obama stands the best shot at getting re-elected by making the election a choice between fairness and greed, with Romney and his corporate allies as the unabashed defenders of a new Gilded Age.