'Dark Money' Groups Will Now Have To Reveal Their Donors

Political nonprofit organizations now have to disclose many of their donors, thanks to a Supreme Court decision Tuesday. The order goes into effect Wednesday, in plenty of time for upcoming midterm elections.

So-called "dark money" groups already had to report their expenditures to the Federal Election Commission but weren't usually required to reveal their donors. The groups use donations to finance political ads during primary and general elections.

On Tuesday, the Supreme Court declined to stay a lower court's ruling that many "dark money" donors must be reported. That decision is going to be appealed.

Issue One, a nonpartisan, nonprofit organization released a report of the top 15 dark money organizations from 2010-2016. It found that together, the groups received almost $763 million from donors — donors they largely weren't required to disclose.

The report said the three largest dark money groups are Americans for Prosperity, which is operated by the Koch brothers; the NRA; and the conservative group, American Future Fund.