WASHINGTON ― The super PAC money swamping the American election system is generally, and rightly, blamed on the Supreme Court’s Citizens United ruling. But a lower court decision that relied on Citizens United ultimately opened the floodgates.

Now a team of high-powered lawyers is seeking to overturn that lower court decision and upend the legal basis for super PACs.

They filed a complaint with the Federal Election Commission on Thursday on behalf of a bipartisan group of congressmen, congressional candidates and advocacy groups. It’s the first step in what will likely be a multiyear legal effort challenging SpeechNow.org v. FEC, ending up before the justices.

“For years, campaign finance defenders have been on the defensive in court,” Ron Fein, a member of the legal team, said at a Capitol Hill press conference on Thursday. “Today that changes.”

Fein works for the anti-Citizens United advocacy group Free Speech for People, which is also a party to the case. Beside Fein, the attorneys taking on super PACs include Norm Eisen, the former ethics czar and ambassador to the Czech Republic under President Barack Obama; Harvard law professor Laurence Tribe; University of Minnesota law professor Richard Painter, a former ethics czar under President George W. Bush; University of Chicago law professor Albert Alschuler; John Bonifaz, president of Free Speech for People; and Anne Weismann, executive director of the nonprofit Citizens for Accountability, which is another party to the case.

The target of their complaint is a 2010 ruling by the U.S. Court of Appeals for the D.C. Circuit. SpeechNow.org v. FEC provides the legal underpinning for independent expenditure-only political committees, more commonly known as super PACs.

The key characteristic of super PACs is that they can accept unlimited contributions from individuals, corporations, labor unions and other political action committees. They were recognized by the FEC after the appeals court in SpeechNow.org ruled that political committees could accept unlimited contributions if they spent money only on independent expenditures and did not donate to candidate campaigns.

SpeechNow.org was decided just two months after the Citizens United ruling. In holding that corporations and unions could spend unlimited sums of their own money on electoral efforts not coordinated with candidates and political parties, Justice Anthony Kennedy declared in Citizens United that such independent expenditures “do not give rise to corruption or the appearance of corruption.” Decades of court rulings had already established that the only permissible reason to limit campaign money is if those restrictions would combat government corruption or the appearance thereof.

According to the D.C. Circuit, Kennedy’s assertion also served to resolve the question of whether the FEC could apply contribution limits to groups like SpeechNow.org.

“In light of the [Supreme] Court’s holding as a matter of law that independent expenditures do not corrupt or create the appearance of quid pro quo corruption, contributions to groups that make only independent expenditures also cannot corrupt or create the appearance of corruption,” the appeals court said.

The D.C. Circuit’s ruling never went up to the high court. The Justice Department declined to seek Supreme Court review because, according to then-Attorney General Eric Holder, “the particularly limited nature of SpeechNow’s contribution and expenditure practices means that the court of appeals’ decision will affect only a small subset of federally regulated contributions.” (Talk about famous last words.)

The complaint challenging SpeechNow.org is aimed at pushing the courts, in particular the Supreme Court, to reconsider that decision in light of how it has actually impacted elections.

The legal team argues that the SpeechNow.org ruling incorrectly extended the Citizens United decision, which concerned independent spending on electoral efforts, to the realm of contributions to political committees. They contend that federal contribution limits should still apply to super PACs.

It’s hard to argue that many super PACs are truly engaging in independent electoral efforts. Legally, they’re not allowed to coordinate with candidates, but in practice a symbiotic relationship has developed between the two groups. Almost all major spending by super PACs comes from those committees that are connected to the candidates themselves or that act as arms of party leadership. High-level staffers routinely decamp from candidate campaigns to run supportive super PACs. Candidates can raise funds for those super PACs, so long as they do not directly ask for a contribution above $5,400 (that’s the current limit). These fundraising events can be as cozy as the candidate and just one or two donors. And campaigns regularly post video and photos of their candidate on the internet for their favored super PACs to use.

As to the question of whether super PAC contributions can corrupt or create the appearance of corruption, Fein pointed out that while candidates cannot technically speak to supportive super PACs about how to spend all that money, they can speak to the donors who make super PAC contributions. Last year’s indictment of Sen. Robert Menendez (D-N.J.) indicates that the Justice Department sees this the possibility for quid pro quo corruption here. Menendez was indicted for allegedly pressuring executive branch officials to intervene on behalf of a donor in exchange for the donor making monetary contributions ― which included $600,000 to a super PAC supporting the senator.

“The complaint that we’re filing today shows that large super PACs do create at least the appearance of corruption,” Alschuler said at the press conference.

The FEC complaint targets 10 super PACs that have spent or are expected to spend large sums of money in congressional races against particular candidates. The individual plaintiffs in the case are Sen. Jeff Merkley (D-Ore.), Reps. Walter Jones (R-N.C.) and Ted Lieu (D-Calif.), and congressional candidates Zephyr Teachout (D-N.Y.), John Howe (R-Minn.) and Michael Wager (D-Ohio). All of them either have faced attacks by super PACs financed by six- or seven-figure contributions, or expect to face them.

“I look forward to a rational court overturning the SpeechNow decision,” said Lieu, who has been hit by two super PACs with big-money donors.

Jones, who was attacked by a Republican super PAC funded by multiple million-dollar donations in his 2014 primary campaign, noted that he is the only Republican House member to co-sponsor legislation to override the Citizens United decision and to create a system of public financing for congressional candidates. He said that joining this case is “probably the greatest honor I have had since being in Congress for 20 years.”

Jones hopes the SpeechNow.org challenge can help “return the power to the people.”

There is some justification for such hope. For several decades now, sympathetic courts have generally sided with conservative proponents of eliminating campaign finance restrictions. But the death of Justice Antonin Scalia, a strong opponent of campaign finance limits, leaves an opening on the Supreme Court, and there’s a reasonable chance that vacancy will be filled by a Democratic president’s nominee. By the time this case could reach the Supreme Court, it might be a much more inviting place for reformers.