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.