EVERY PRESIDENTIAL election campaign, it seems, heralds a further erosion of laws that are meant to restrict the influence of money in politics. In years past, outside groups known as 527s pumped millions into electing favored candidates. The system of partial public financing for the primary campaign and full federal funding for the general election became increasingly obsolete, with candidates able to raise millions more on their own. The 2012 campaign brings with it a dangerous new twist: the ascendance of the candidate-specific “super PAC.”

Thanks to the Supreme Court, a super PAC can accept donations of any amount from corporations, labor unions and wealthy individuals. Then, this supposedly independent entity can make supposedly independent expenditures to boost the presidential fortunes of its favored candidate. Why supposedly? Because in practice these political action committees tend to be set up by longtime supporters and former aides of the candidate. Because in practice the money comes from the candidate’s longtime donors. Because “independence” in the lazy eyes of the Federal Election Commission has been drained of all real meaning.

Thus former Massachusetts governor Mitt Romney was free to attend — and even make his presidential pitch at — an event put on by a pro-Romney super PAC, Restore our Future, that is run by former Romney campaign aides. Indeed, under the FEC’s rules, candidates can raise money for super PACs that support them, as long as the donations are within the limits for ordinary contributions. If a supporter is moved by the candidate’s pitch to write a bigger, separate check — well, that’s not the candidate’s fault.

The emergence of the super PAC is a bipartisan phenomenon. Two former campaign and White House aides for President Obama have launched Priorities USA Action to help the reelection effort. Texas Gov. Rick Perry, Minnesota Rep. Michele Bachmann and former Utah governor Jon Huntsman each have super PAC backing.

The underpinning of federal campaign finance law — that donations should be limited in size (the ceiling for contributions to candidates is $2,500) — threatens to be washed away by the emergence of the super PAC. According to a report by the Center for Public Integrity, Hollywood executive Jeffrey Katzenberg wrote a $2 million check to Obama-supporting Priorities USA. The Romney-backing Restore Our Future has received five $1 million checks, including from mysteriously named companies such as Eli Publishing and F8 LLC of Provo, Utah. Moreover, there is no reason to expect that this development will stop at presidential candidates. If history is a guide, soon dozens of congressional races will feature super PACs as well.

The source of this problem is easier to identify than its solution. The Supreme Court, in its Citizens United ruling , allowed corporations to make unlimited independent expenditures on behalf of federal candidates, finding that such activities did not pose a serious risk of corruption. In the aftermath of Citizens United, the federal appeals court in the District of Columbia, ruling in a case called Speech Now, said the same rationale permitted unlimited individual contributions to PACs that make independent expenditures.

Whether the right approach is to press for tighter regulations or new legislation, this much is clear: The growth of the super PAC threatens to make limits on campaign contributions a mere fig leaf barely covering the reality of outsize checks — for which the candidates are undoubtedly grateful to the donor.