For the last 10 years, the Supreme Court has engaged in a systematic effort to transform American democracy. Steered by Chief Justice John Roberts, the Court loosened restrictions on political advertising by corporations and unions, gutted a key provision of the Voting Rights Act, upheld the rights of states to enact restrictive voting laws, and, in the words of Justice Stephen Breyer, “eviscerate[d] our Nation’s campaign-finance laws.” This year, the Court will decide a voting and redistricting case that could change the lines of virtually every state legislative district in the country. There is no area of the law the Roberts Court has more thoroughly transformed.

Almost all of the Court’s major election cases were decided by a 5-4 vote. Of course, on the Court, the majority rules. But it would not take a constitutional amendment or a revolution in legal scholarship to bring this string of decisions to an end. It is extremely likely that the next president will have the opportunity to replace at least one (and very likely more than one) Supreme Court justice, as the previous five presidents have done. One new justice on the Court might be enough to push the law in the opposite direction.

Today, super PACs enable the very wealthiest to spend unlimited amounts on campaigns. It’s hard to remember that they didn’t even exist before 2010. That year, the top 100 donors spent less than one third as much as the total contributions of all small donors to federal candidates. By 2014, that drastically changed. The top 100 super PAC donors spent almost as much as the combined total contributed to candidates by all small donors.

Super PACs are a legacy of the Roberts Court’s 5-4 decision in the Citizens United case. At the heart of that ruling was the assumption that independent election spending does “not give rise to corruption or the appearance of corruption.” Three months later, in SpeechNow, a lower court made the logical inference that if independent spending does not corrupt, there is no reason to limit contributions to independent spending groups. Thus “independent-expenditure-only PACs,” soon to be called super PACs, were born.

Could super PACs be banned if Citizens United and SpeechNow were reversed? In a word, yes. In fact, the first court to hear SpeechNow held to what had been the standard before Citizens United, noting that the Supreme Court “ha[d] never held that, by definition, independent expenditures pose no threat of corruption,” and that a group’s legal “independence” does not prevent it from forming close ties with officeholders that could lead to corruption. If a new Court were to accept this reasoning, it could restore the ban on super PACs by upholding the $5,000 limit on donations to political committees; Congress or the Federal Election Commission (FEC) could do the same if the Court overruled Citizens United.

Another of the cornerstones of the Roberts Court’s laissez-faire approach to money in politics is that disclosure will prevent the corruption that can accompany a system dominated by big money. In Citizens United, the Court rejected the challengers’ objections to federal-disclosure rules, explaining that “the public has an interest in knowing who is speaking about a candidate shortly before an election.” Yet without question, Citizens United and its predecessor, Wisconsin Right to Life, created the conditions that led to the rise of dark money.

Wisconsin Right to Life was decided in 2007 by a 5-4 vote in which there was no majority opinion on several key points, meaning that the controlling opinion written by Roberts effectively became the law. Roberts’s opinion held that corporate and union campaign spending could be prohibited only if their ads contained “express advocacy”—explicitly calling for the election or defeat of a named candidate—or its “functional equivalent,” by using terms that are susceptible of no other reasonable interpretation. This left a gaping loophole for unlimited spending on ads ostensibly made to educate voters on issues of the day, but clearly intended to bolster one candidate or damage another.

Worse, outside groups seized on this bright-line rule to avoid disclosure. They argued, with the support of half the FEC, that provided they were not spending extensively on express advocacy, they did not need to register as political committees. Yet status as a political committee triggers most campaign-finance disclosure obligations. While there are also some disclosure requirements for each communication, FEC rules have made those exceptionally simple to evade as well. As a result, money contributed to outside groups is easily concealed and the “prompt disclosure” imagined by the Roberts Court in theory is often illusory in practice. In 2008, the first election after Wisconsin Right to Life, federal dark-money spending increased from almost nothing to about $70 million. It continued to rise quickly, reaching almost $310 million in 2012.

Combined with Citizens United’s allowance for unlimited “independent” spending, and a Congress that appears unwilling to pass legislation that would reimpose more disclosure, these decisions have enabled secret spending to influence politics on a scale not seen since the Gilded Age.  

Citizens United is perhaps best known for declaring that corporations (and, by extension, labor unions) have a First Amendment right to spend unlimited money on elections. Corporate political spending is often difficult to track, but IRS data shows that in 2012, corporations gave at least $173 million to nonprofit groups that spend in elections. Such groups are frequently used to obscure the source of political spending.

While corporations and unions certainly spent in elections prior to Wisconsin Right to Life and Citizens United, there were strict limits on their spending. Congress first regulated corporate spending in 1907 with the Tillman Act, preventing corporations from making any “money contribution in connection with any election to any political office.” Almost 100 years later, the Bipartisan Campaign Reform Act (BCRA) barred corporations and unions from using funds from their general treasuries to buy broadcast ads that targeted specific candidates. These rules prevented corporations or unions from spending huge sums on federal elections.

The four dissenters in Citizens United tried to explain “why corporate electioneering is not only more likely to impair compelling governmental interests, but also why restrictions on that electioneering are less likely to encroach upon First Amendment freedoms.” To impose restrictions on corporate and union spending in elections would take only a return to a status quo that prevailed before Citizens United.

In last year’s 5-4 ruling in McCutcheon v. FEC, the majority gave its clearest expression yet of its attitude on money and politics. Campaign-finance limits, the Court said, may only be used to protect against quid-pro-quo corruption, “a direct exchange of an official act for money.” The Court did away with a limit that capped combined contributions in a single election cycle to all federal candidates and parties at about $123,000.

Though McCutcheon was decided only seven months before the 2014 election, nearly 700 donors managed to exceed the old limits, contributing more to candidates and political parties than was previously allowed. Both the number of these mega-donors and the size of their contributions are likely to grow substantially in 2016.

In practice, however, these mega-donors do not write small checks to hundreds of federal candidate, state, and local party committees. Instead, they write a small number of huge checks to joint fundraising committees that distribute the money. Congress further encouraged this practice in 2014 when it tucked a provision into must-pass legislation creating new party accounts that could accept contributions of more than $100,000. As the chart below shows, in just one year the maximum amount an individual could contribute to federal candidates and political parties increased from $123,200 to nearly $5 million.

In his McCutcheon dissent, Justice Breyer argued that the Court had substituted its understanding of the political process for that of Congress, and failed to appreciate that undue influence itself is a form of corruption that can, and should, be addressed by campaign-finance regulation. By returning to a broader definition of “corruption,” one that reflects the range of threats posed by big money in politics, the Court could reduce the influence of mega-donors on elections.

Citizen-funded elections, which provide public funds to candidates who agree to abide by strict fund-raising and spending limits, aim to ensure that ordinary Americans—not just the wealthy and well connected—can run credible campaigns for elected office. Perhaps more importantly, they aim to ensure that successful candidates need not depend on wealthy donors to support their campaigns. These programs exist in various forms in dozens of states and cities across the country.

But in Arizona Free Enterprise in 2011, the Supreme Court struck down a key element of many of these programs. In another 5-4 decision, it rejected the “trigger matching fund” provision of Arizona’s public-financing law, which provided extra money to candidates using the program when privately supported candidates exceeded a certain spending threshold. The purpose of the provision was to ensure that publicly financed candidates could still get their message out in the face of massive private spending.

The notion of any sort of government-funded attempt to strike a rough parity between candidates is anathema to Roberts and his allies. In the majority opinion, Roberts wrote, “We have repeatedly rejected the argument that the government has a compelling state interest in ‘leveling the playing field’ that can justify undue burdens on political speech.”

The impact of the Court’s ruling was immediate. Eighteen Arizona candidates who had used public funding before switched to private funding in the first election after the ruling. In 2010, before the decision, both major-party gubernatorial candidates used public financing. Four years later, neither did. Likewise, candidates in other states with public financing programs, such as Maine and North Carolina, also abandoned them in large numbers.

The Arizona decision did not kill all public-financing systems. Programs in New York City and Connecticut that do not rely on trigger funds continue to thrive. In 2013, New York City’s program saw a 92 percent participation rate during the primary and 72 percent during the general election. One year earlier Connecticut saw record participation in its program.

It is possible to craft public-financing systems that do not run afoul of Arizona Free Enterprise. Yet the decision constrains the types of public-financing systems that can be enacted, and makes it hard to for publicly financed candidates to compete. As Justice Elena Kagan, quoting Citizens United, put it in the dissent, “By enabling participating candidates to respond to their opponents’ expression, the statute expands public debate, in adherence to ‘our tradition that more speech, not less, is the governing rule.’”

There are few issues in the last decade on which the Court has been so consistently and bitterly divided as it has over campaign-finance law. Justice Ruth Bader Ginsburg recently decried “what has happened to elections in the United States and the huge amount of money it takes to run for office.” She argued that eventually, “sensible restrictions” on campaign financing will again be in place because “the true symbol of the United States is not the eagle, it’s the pendulum—when it swings too far in one direction, it will swing back.”

On the Court, that swing back only requires one new or existing justice to adopt the approach of four current members. A shift in the Court could permit reasonable regulation of big money in politics. To be sure, state and federal legislators would need to pass new laws to regain the ground that has been lost, and mere reversal of campaign-finance decisions of the last decade would not solve all of the problems of excessive influence. Because of older Supreme Court decisions, for example, new laws still could not limit the total amount of spending in any election.

Still, it is no exaggeration to say that the next appointments to the Supreme Court will have a profound impact on political power in the United States. The appointment of one or more justices who agree with the five-member majority might solidify the current system for decades to come. By contrast, appointment of one or more justices who share the vision of the Court’s four-member minority could bring substantial power over elections and the political process back to ordinary Americans.