A majority of the United States Senate has voted to advance a constitutional amendment to restore the ability of Congress and the states to establish campaign fundraising and spending rules with an eye toward preventing billionaires and corporations from buying elections.

“Today was a historic day for campaign finance reform, with more than half of the Senate voting on a constitutional amendment to make it clear that the American people have the right to regulate campaign finance,” declared Senator Tom Udall, the New Mexico Democrat who in June proposed his amendment to address some of the worst results of the Supreme Court’s interventions in with the recent Citizens United v. Federal Election Commission and McCutcheon v. Federal Election Commission decisions, as well as the 1976 decision in Buckley v. Valeo.

That’s the good news.

The bad news is that it’s going to take more than a majority to renew democracy.

Fifty-four senators, all Democrats and independents who caucus with the Democrats, voted Thursday for the amendment to clarify in the Constitution that Congress and the states have the authority to do what they did for a century before activist judges began intervening on behalf of wealthy donors and corporations: enact meaningful campaign finance rules and regulations.

But forty-two senators, all Republicans, voted no. As a result, Udall noted, the Republican minority was able to “filibuster this measure and instead choose to support a broken system that prioritizes corporations and billionaires over regular voters.”

The Republican opposition effectively blocked further consideration of the amendment proposal, since sixty votes were needed to end debate and force a vote. And, even if the Republicans had not filibustered the initiative, actual passage of an amendment would have required a two-thirds vote.

Though the Republican move was anticipated, Senator Bernie Sanders, the Vermont independent who has been one of the Senate’s most ardent advocates for reform, expressed frustration with the result. “I am extremely disappointed that not one Republican voted today to stop billionaires from buying elections and undermining American democracy,” said the senator, who has advocated for a more sweeping amendment to address the influence and power of corporate cash on American elections and governance. “While the Senate vote was a victory for Republicans, it was a defeat for American democracy. The Koch brothers and other billionaires should not be allowed to spend hundreds of millions of dollars electing candidates who represent the wealthy and the powerful.“

Now, said Sanders, “the fight to overturn Citizens United must continue at the grassroots level in every state in this country.”

Sanders is right to reference the role of grassroots movements.

Four years ago, when the US Supreme Court removed barriers to corporate spending to buy elections, serious reformers said a constitutional amendment would be necessary to reverse the Court’s Citizens United ruling. Most pundits and politicians, even those who recognized the threat posed to democracy by the opening of the floodgates for big money, dismissed a constitutional fix as too bold and too difficult to achieve.

But the people embraced the constitutional route to reform. Grassroots organizing succeeded in getting sixteen states and close to 600 communities to formally demand that Congress act.

At the same time, the money poured in, with campaigning spending breaking records in the 2012 presidential and congressional elections—and heading toward breaking the record for midterm elections in 2014.

That was enough to shake up even the most cautious Senate Democrats, who began moving earlier this year to advance the Udall amendment. Though activists wanted a stronger amendment, the Senate deliberations confirmed that there is broad support for a constitutional response to the money-in-politics mess—and that a substantial number of senators now see that constitutional response as right and necessary.

“Less than five years after the Citizens United decision sparked national outrage, we have seen the movement to get big money out of politics go from local, grassroots organizing to a vote in the United States Senate,” explained People for the American Way Executive Vice President Marge Baker, who worked with activists from Public Citizen, Common Cause, Free Speech for People and other groups to collect and deliver 3.2 million signatures on petitions supporting an amendment. “Today’s historic majority vote is a remarkable milestone for this movement and a platform for taking the fight to the next level. The debate in the Senate this week is a debate that Americans across the country who are passionate about fixing our broken democracy have wanted to see.”

With the DC debate done, for now, the fight goes back to the grassroots. Activists with groups such as Move to Amend, Public Citizen’s “Democracy is for People” campaign and Free Speech for People will continue to organize and agitate, not just for an amendment but for an amendment that makes it absolutely clear that money is not speech, that corporations are not people and that citizens have a right to organize elections where votes matter more than dollars.

“We have amended the US Constitution before in our nation’s history. Twenty-seven times before. Seven of those times to overturn egregious Supreme Court rulings. For the promise of American democracy, we can and we will do it again,” declared John Bonifaz, the president of Free Speech for People, said Thursday. “The pressing question before the nation today is whether it is ‘we the people’ or ‘we the corporations and big money interests.’ This not a Democratic issue or a Republican issue. This is a deeply American issue. Whatever our political differences may be, we all share the common vision of government of, for, and by the people. Today’s US Senate vote is just the beginning. While this amendment bill did not receive this time the required two-thirds support in order to pass the Senate, we will be back again and again until we win. History is on our side.’