Who's Funding the 2016 Election? Mostly, We'll Never Know.

Dark money groups have spent $143 million on the 2016 U.S. presidential election since last July—nearly four times as much as the candidates’ own campaigns, Politico reported in a new analysis on Tuesday.

The origins of most of that funding will never be revealed, while some of it will be made public at midnight on January 31, just hours before the Iowa caucuses, writes Politico‘s chief investigative reporter Kenneth P. Vogel.

With federal regulators struggling to navigate the election landscape in the wake of the Supreme Court’s 2010 Citizens United v. FEC decision, outside groups are having an increasingly powerful influence over the proceedings, Vogel found.

“Every day, we learn more and more about how super PACs and other outside groups are working extremely closely with federal candidates,” said Federal Election Committee (FEC) member Ann Ravel.

While the Supreme Court’s Citizens United decision opened the door to unlimited campaign spending by outside groups like corporations and super PACs, the blame is also shared by the FEC itself, which has been criticized for its toothless approach to regulating the flow of dark money, Ravel said.

In the intervening years since they handed down the decision, it’s become clear justices “did not understand what the implications were going to be of what they did,” she continued, adding that enforcing transparency and preventing coordination between candidates and their supporting groups “are the two issues that are the most frustrating, because the court was very clear about it and the law is very clear about it, but it’s clear that this is not the reality in the 2016 election.”