The Massachusetts Democrat brought her populist platform to about 450 prospective voters at Manchester Community College, taking aim at the "wealthy and well-connected" and championing economic reforms to benefit the middle and lower classes.
"This is about who the rules work for," she said. "Is it just going to be for the wealthy and well-connected, or is it going to be for everyone else?"
Afterward, she made her pitch to a more select group at a house party in Concord, the state's capital.
Warren promised "the biggest anti-corruption proposal since Watergate," but did not mention by name the likely inspiration for her proposal — President Donald Trump. "I think (Democrats) need to talk about our affirmative vision," and not Trump, she told reporters afterward.
The sweeping reform plan unveiled in August would crack down on foreign lobbying and lobbyist campaign donations, as well as launch an independent federal anti-corruption agency and require that Supreme Court justices be bound by the same ethics rules as other federal judges.
This was Warren's first visit to New Hampshire since launching an exploratory committee for the 2020 campaign. Besides advocating for reforms to health care, student debt, and the minimum wage, Warren touched on breaking news with a call for an end to the ongoing partial federal government shutdown, which is now the longest in history.
"Federal workers are not pawns," she told a crowd of about 60 pressed into a Concord living room. "(Opening the government) is the job right now of the U.S. Senate, and we have votes to do it, and (Senate Majority Leader) Mitch McConnell is holding us back."
If Sen. Bernie Sanders declares another presidential run, Warren could face a strong opponent in the New Hampshire primary, which the Vermont independent took in 2016 by a 22-point margin over Hillary Clinton.
Yet Warren's supporters Saturday said Sanders's moment had passed, leaving her to take up the progressive banner.
"Bernie's terrific. His politics are right on," said John Schipp, of Wolfeboro, N.H. "But I think we need someone a little younger, a little stronger." He added, "Someone with mass appeal. Someone who owns a comb."
Warren also will confront persistent questions about her claims to Cherokee heritage. This fall, she released a DNA test in response to President Trump's "Pocahontas" jibes against her, but faced backlash from Native tribe members who felt the distant connection revealed by the test was an unfair comparison to their own indigenous ties.
Protesters at the entrance to Manchester Community College recalled that dispute, with one demonstrator wearing a makeshift feather headdress and others hoisting signs that read "Taxation Is Theft."
Other prominent Democrats have already jumped in the race, including Tulsi Gabbard, a congresswoman from Hawaii, and Julian Castro, a former secretary of housing and urban development under Barack Obama.
Although Warren has not formally declared her candidacy, she appeared well on her way to the campaign trail, telling supporters "this is going to be a grassroots campaign," one without unaccountable PAC money or lobbyist donations.