Andrew Burton/Getty Images Zephyr Teachout, seen here during her primary challenge to New York Gov. Andrew Cuomo on Sept. 9, 2014, in New York City.

Progressive Democrat Zephyr Teachout lost one of the hardest-fought House races in the country Tuesday night, narrowly edged out by Republican John Faso in the contest to represent New York’s 19th District.

Teachout’s fiery attacks on corporate monopolies and political corruption have made the race a key battleground for the progressive wing of the Democratic Party represented by Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.).

“Once a century a generation is called on to restore American democracy. Today our generation is called,” Teachout said in a concession statement Tuesday night. “And if there’s one thing I learned on the campaign trail ― it is that we are more than brave enough and more than smart enough to take our democracy back. This is our moment. We may have lost this race, but we’re not going away.”

Teachout drew fierce financial opposition from three billionaires, turning the race into a microcosm of her critique of post-Citizens United politics. Hedge fund kingpins Robert Mercer and Paul Singer each poured at least $500,000 into a super PAC devoted to defeating Teachout, a tremendous sum for a single House race.

Teachout’s fundraising brought in more than $1.6 million, relying on smaller donors who made an average contribution of $19. Informed by her academic study of U.S. political corruption, Teachout advocated public financing of elections and the repeal of Citizens United, while her economic platform called for breaking up big cable companies, forcing banks to lend to small businesses, and raising taxes on hedge fund magnates.

In a speech to supporters late Tuesday night, she invoked the legacy of President Franklin Delano Roosevelt.

Faso is a former state assemblyman who made an unsuccessful bid for governor in 2006 against Eliot Spitzer. He eventually joined the law firm Manatt Phelps & Phillips as a lobbyist, where he was entangled in an ethics scandal involving New York state pension funds. The firm paid $550,000 in 2010 in a settlement that cited a meeting Faso arranged between an investment client and a state retirement fund.

Faso attacked Teachout during the campaign as a tax-hiking purveyor of a “crazy liberal agenda,” and vowed to cut government spending and the national debt. The National Republican Congressional Committee ran an ad on behalf of Faso that dismissed Teachout as a “zany professor” in the Sanders mold.

Teachout didn’t exactly hide her association with Sanders, who appeared at a rally on her behalf in September and helped to raise funds for her campaign.

“This is about whether or not super PACs and big money can buy a seat in Congress to protect their profits, or if a grassroots movement will succeed,” Sanders wrote in an email to Teachout supporters last week. “These billionaires know that [Teachout] will fight in Congress to take on corruption, stop bad trade deals, and fight for working people.”

New York’s 19th District went for President Barack Obama in both 2008 and 2012, but its largely rural, white and working class electorate has been represented by Republican Chris Gibson since 2013.

Teachout’s full concession statement is below:

I am so incredibly proud of this campaign. We gave the billionaires trying to buy our elections a real run for their money-faceless men, cowards who spent $6.7 million to shut us up-but we barked back with an average contribution of $19. It’s because of the parents, teachers, veterans, farmers, and small business owners in the 19th Congressional District that this race was as close as it is. We showed them that we the people will not be dictated to, and our fight continues. Once a century a generation is called on to restore American democracy. Today our generation is called. And if there’s one thing I learned on the campaign trail – it is that we are more than brave enough and more than smart enough to take our democracy back. This is our moment. We may have lost this race, but we’re not going away. We can still stop the TPP. We can still stop the AT&T merger. We can and must organize to overturn Citizens United. We are the unique threat they fear.

This post has been updated with Teachout’s concession statement.