It will be a year this week since Chief Justice John Roberts and his conservative activist colleagues on the Supreme Court joined together in a dramatic assault on American democracy. Their decision in the Citizens United case overturned more than a century's worth of precedent by awarding corporations the rights of citizens with regard to electioneering. The court did away with limits on when corporations can spend on elections, how much they can spend and how they can spend their money, allowing unlimited contributions from corporate treasuries to flood the electoral landscape.

As The Nation noted in the days after the case was decided, "This decision tips the balance against active citizenship and the rule of law by making it possible for the nation's most powerful economic interests to manipulate not just individual politicians and electoral contests but political discourse itself."

According to Bill de Blasio, New York City's public advocate, Citizens United spending - that is, spending that was only made possible by the court's ruling - accounted for 15 percent of the roughly $4 billion spent on the 2010 midterm elections. Eighty-five million dollars of Citizens United money was spent on U.S. Senate races alone. Worse, 30 percent of all spending by outside groups was funded by anonymous donations, an illegal action prior to the ruling. Forty million of the dollars spent on Senate races came from sources that might never be revealed.

But as striking as these consequences might be, the 2010 election was just an experiment, the first opportunity to test the new law. In future elections, corporations and shadowy organizations will have a clearer understanding of the boundaries they are operating within, a reality that is sure to translate into more undisclosed cash. And the savvier corporate players know that the mere threat of a corporate onslaught of funding for or against a candidate is enough to win legislative favor, in effect blunting prospects for sound regulation, consumer protection and fair tax policies. As former senator Russ Feingold (D-Wis.), himself a victim of Citizens United spending, said, "It is going to be worse in 2012 unless we do something - much worse."

Yet even as we lament this decision, we should recognize the opportunity it presents. Justice Roberts and his allies overreached so brazenly that they have created an opening for genuine reform.

There are multiple steps that can be taken, both short-term and long-term, to roll back the corrosive impact not just of Citizens United but of preceding campaign finance cases and statutes that already had flooded the electoral landscape with special-interest spending. At the more modest end of the spectrum is the option of reviving the Disclose Act or introducing similar legislation that would require corporations to show how they spend money on elections and provide disincentives to spending it. This would be a good step, but it is mere triage; if not accompanied by a broader push for a bolder set of reforms, its success would do little to curb the corporate takeover of American elections.

One potential policy change that could accompany greater disclosure would be the introduction of a public financing system, which would empower small donors. Legislation has already been introduced in Congress - the Fair Elections Now Act, which has more than 160 supporters in the House. A similar system has been adopted in Arizona, and, in 2007, New York City adopted an intriguing mechanism of public finance in which the city matches small donations at a 6-1 ratio, boosting grass-roots fundraising.

The result? According to the New York Times, the changes "drastically curtailed the role of businesses, political committees and lobbyists in campaigns" and, importantly, "caused a major drop in donations from those doing business with the city." Such a system, implemented on the national level, could greatly increase the influence of average citizens. In the post-Citizens United era, there are already efforts afoot to weaken such systems. In Arizona, for example, the Chamber of Commerce is working aggressively to overturn the state's clean-money legislation. A push for national public financing, then, must be accompanied by a strong defense of those systems already in place.

The clearest and boldest counter to the court's ruling would be a constitutional amendment stating unequivocally that corporations are not people and do not have the right to buy elections. Rep. Donna Edwards (D-Md.) introduced such an amendment to counter Citizens United during the last session of Congress and views it as the only sure way to beat back the court. "Justice Brandeis got it right," she noted last February. " 'We can have democracy in this country, or we can have great wealth concentrated in the hands of a few, but we can't have both.' "

Campaigns for constitutional amendments demand a great deal of patience and tenacity. But as Jamie Raskin, a Democratic Maryland state senator and professor of constitutional law at American University, notes, "American citizens have repeatedly amended the Constitution to defend democracy when the Supreme Court acts in collusion with democracy's enemies." Not only is a push for an amendment a worthy act, it also provides a unique opportunity to educate the broader public, raise the profile of this important issue and force elected officials to go on record as to where they stand. The campaign could create enormous pressure on state legislatures and Congress, prompting changes to campaign finance even before an amendment is ratified.

Success will require a coalition that transcends party. In this case, there is promising news. An August 2010 Survey USA poll found that 77 percent of all voters - including 70 percent of Republicans and 73 percent of independents - view corporate spending in elections as akin to bribery. Broad majorities favor limiting corporate control over our political lives. A coordinated effort, executed right, could unite progressives, good-government reformers and conservative libertarians in a fight to restore democracy.

The multitude of reform groups working to build a more just and democratic political system understand that if this issue is to grip people's imaginations, it must be about more than process. In a nation where recovery still feels like recession, the suffocating grip of corporate money is anything but abstract. Mobilizing the American people to make reform a priority will demand making the clearest possible link between the rise of corporate power and the challenges of everyday lives.

That's not a tough pitch.

In just the past two years, corporate money can be blamed for watering down consumer protections and diluting health-care and financial reform. In truth, there is almost no conversation we have in American politics in which corporations don't occupy all the seats at the table. As Sen. Dick Durbin (D-Ill.) acknowledged while talking about big banks during last year's financial reform debate: "They frankly own the place."

Changing that dynamic might well be the central challenge of this generation. Reversing Citizens United is about more than any one issue or court case - it is, at its base, a question of whether American democracy itself can beat back a corporate takeover, whether our most cherished principles of self-government can ultimately prevail.

Katrina vanden Heuvel is editor and publisher of The Nation. She writes a weekly online column for The Post.