PROVIDENCE, R.I. — With a voice hoarse not from last week’s Massachusetts Democratic convention, but from “the parties,” she said, Elizabeth Warren took the stage at the annual Netroots Nation conference here Friday afternoon with a clear goal: link her GOP opponent, Sen. Scott Brown, to the presumptive GOP nominee, Mitt Romney.

Massachusetts Democratic Senate nominee Elizabeth Warren. (Steven Senne — Associated Press)

The Harvard professor and Democratic Senate nominee made no mention in her 10-minute remarks of the months-long flap over her Native American heritage, an imbroglio that the Brown campaign as seized upon and that polls suggest could take a toll on Warren in November.

Rather, Warren’s only allusion to the episode came as she told the cavernous hall of nearly 3,000 progressive activists that she remains determined to stay in the race for the same reasons she jumped into it.

“Let me make clear, I am not backing down,” Warren said to loud applause.

As she seeks to unseat Brown in what stands to be among this year’s most competitive (and expensive) Senate battles, Warren on Friday repeatedly took aim at “the Romney-Brown Republicans” on matters ranging from her signature issue of financial regulatory reform to campaign finance and the battle over health insurers and contraception.

“The Republican nominee, Mitt Romney, said, ‘Corporations are people.’ No, Mitt, corporations are not people,” she said to cheers. “People have hearts. They have kids. They get jobs. They get sick, they laugh, they cry, they dance, they live and they die. Learn the difference.”

After pausing again for a long round of applause, Warren added: “And Mitt, learn this. We don’t run this country for corporations, we run it for people.”

As Democrats on Capitol Hill and on the campaign trail have done frequently this year, Warren honed in on the theme of income inequality, arguing that markets represent the “place where the most powerful come to hammer on the least powerful.”

“Progressives understand that markets are like football — that every game needs rules and a referee,” she said, then added with a sigh: “Without rules and a referee, it isn’t football. It’s a mugging.”

And she told the crowd that while she is running for office, she in search of “something more than winning an election.”

“I want to change the national conversation,” she said. “I want real change. It’s up to us to put the wind in our own sails. With your support, I know we can do this.”

Shortly after delivering her keynote address, Warren joined a panel of other women running for office including Rep. Mazie Hirono (D-Hawaii), who is running to succeed retiring Sen. Daniel Akaka (D-Hawaii), and former Microsoft product manager Darcy Burner, a third-time candidate who is running for the Democratic nod in Washington’s 1st Congressional District.

In response to a question by moderator Angela Terkel of The Huffington Post regarding recent polls showing the low public approval rating of the national health care law, Warren argued — as House Minority Leader Nancy Pelosi (D-Calif.) did at a news conference a day earlier — that Democrats still have not done a good enough job of explaining the benefits of the 2010 law.

“How much have we made the case for what’s in health care reform?” Warren asked. “How much have we sold it? The answer is not very much. ... We need to explain to the American people every single day what the benefits are of the Affordable Care Act.”

One of the themes of the three-day confab has been the changes in the electoral process brought about by the Supreme Court’s Citizens United decision allowing unlimited spending by corporations and unions.

Warren contended Friday that the ruling “is enormously dangerous to all of us,” arguing that it “is effectively the United States Supreme Court saying that the largest and most powerful corporations can grab the electoral process by the throat, and they can squeeze as hard as they want.”

And while Warren and Brown have signed a pact discouraging spending by outside groups on their race, the Democratic nominee continued to hammer her opponent on the campaign finance issue, arguing that Brown “was the deciding vote to kill the DISCLOSE Act,” the 2010 measure that would have tightened reporting requirements for corporations and nonprofits.

When it comes to Warren’s appeal among progressives at the Netroots conference, the Native American heritage controversy appears to have taken little toll: The candidate was swarmed by supporters as she made a brief exit from backstage and down a nearby hallway for a discussion with Massachusetts reporters.

Elizabeth, a 29-year-old nonprofit worker and first-time Netroots attendee from New York City who declined to give her last name, said that she believes that Warren has told the truth about her heritage and that the issue has been “taken out of proportion.”

In defending Warren, she pointed to her own experience as the daughter of a Latino man and a Caucasian woman.

“Most people assume I’m white,” she said. “I have heritage that includes people of color. And Elizabeth Warren has that also. ... I believe in the United States that being Native American is defined differently legally than other (ethnicities).”