Total outside spending for the 2016 election has already reached a record $660 million, more than twice the $289 million spent by outside groups by this point in the 2012 election.

Super PACs have led the charge, breaking the half-a-billion dollar mark in spending and making up about 80 percent of total outside spending. The nearly $530 million is almost three times the amount spent by super PACs in the 2012 election by the end of August. And by the end of the 2012 contest, that $177 million had skyrocketed to $609 million, so expect the groups to burn through much more cash by the time voters cast their ballots this November.

On the receiving end, super PACs are breaking another record, raising just short of $1 billion. For context, these groups pulled in about $828 million in the entire 2012 election cycle.

The two biggest spending super PACs? Conservative groups that supported candidates who dropped out several months ago, Right to Rise USA, which supported former Florida Gov. Jeb Bush, and Conservative Solutions PAC, which propped up Florida Sen. Marco Rubio. The two groups still maintain a lead overPriorities USA Action, which backs Democratic presidential nominee Hillary Clinton— though that will change.

Dark money

While super PACs have poured a record amount of cash into this election cycle, spending by dark money groups and politically active nonprofits overall has slowed compared to its volume in 2012.

By this time in 2012, 501(c) nonprofit groups had spent about $63 million, or about 22 percent of all $289 million in outside spending. But so far this cycle, these nonprofits reported outlays of $62 million — a mere 9 percent of the $660 million in total outside money spent.

Dark money groups, which include mainly 501(c)(4) social welfare organizations and 501(c)(6) business leagues, seem to have taken an even bigger cut, having spent about $75 million by the end of August four years ago, but only $52.9 million to date in this cycle.

(Not all 501(c)s are considered “dark money” groups. Some partially or fully disclose their donors. Also, some super PACs, though required to reveal their donors, disclose only contributions from dark money groups, and thus we classify them as dark money outfits themselves.)

By the end of 2012 election cycle, total 501(c) spending had skyrocketed to $308 million. We’ll likely see another jump this fall, though the slower pace of that spending in recent months makes any predictions tricky. Earlier this cycle, dark money spending was well ahead of 2012 levels.

Contrary to the 2,300 percent increase in overall 501(c) spending from January to August in 2012, that spending has increased only by 680 percent in the same period in 2016.

This slowdown comes unexpectedly; a recent study by the Wesleyan Media Project and the Center for Responsive Politics detailed the escalating role of dark money groups in outside spending since 2000.

Americans for Prosperity, a well-known 501(c)(4) nonprofit in the conservative Kochbrothers network, has limited its involvement in the 2016 election cycle to $2 million so far, considerably less than the $36.6 million it spent four years ago.

Besides the drop in spending, there are considerably fewer nonprofit groups spending money in federal elections this time around, according to FEC reports filed. In the 2012 election cycle, 266 501(c) groups were active election spenders; in this election cycle, just 87 have been.

Craig Holman, government affairs lobbyist at Public Citizen, said this might look surprising at first glance.

“But it does make sense, because this is a very unique election with Donald Trump’s presence,” Holman said. “Donald Trump has alienated corporate interests,” who can be big players in the dark money world. Holman called the dwindling of dark money groups in this election, especially since the conventions, part of a “Trump phenomenon,” and said he does not expect it to be a continuing trend.

Still, the decline also could be simply part of the natural evolution of campaign finance as rules and donor interests change, said Brendan Glavin at the Campaign Finance Institute, a nonpartisan research and advocacy group.

“When soft money became legal in 2002, 527 groups thrived in 2004,” Glavin said. “In 2008, nonprofits started to be exploited more and since 2010, super PACs have started to take over all other spending. We don’t really know what will happen in the next election.”

Federal Election Commission rules allow 501(c) groups to spend millions without reporting any to the commission as long as the ads are run more than 30 days before a primary or 60 days before a general election. Some of the largest politically active nonprofits use these windows to avoid reporting millions of dollars in political spending.

The collaborative study by Wesleyan Media Project and CRP shows nonprofits have deliberately avoided spending during the FEC reporting window, making the reported numbers something of a fiction. One group, a 501(c)(4) called One Nation, has spent tens of millions of dollars in tight Senate races in 2016. The scale of its spending this cycle alone is high enough to put it in the top 50 all-time ad buyers, but it hasn’t reported any of its spending to the FEC.

Over the years, Americans for Prosperity has run more than 90 percent of its adsoutside the FEC reporting windows.

The U.S. Chamber of Commerce, a 501(c)(6) trade association, has held its place as the biggest-spending dark money nonprofit, laying out about $20 million by Aug. 31, 2016.

	2012	2014	2016 (as of Aug. 31)
Super PAC spending	$609,417,654	$345,163,595	$529,622,999
501(c) spending	$336,516,934	$163,259,319	$62,069,989
Number of active super PACs	255	238	230
Number of active 501(c)s	266	157	87

Megadonors

Unlike the 2012 cycle, in which four of the 10 top-spending groups were liberal, only two are liberal in this election cycle.

But despite the fact that there are more conservative outside spending groups, the single biggest individual donor, Thomas Steyer, is a liberal. As of August, 2016, Steyer has given a total of $38 million to a number of liberal super PACs such asNextGen Climate Action, America Votes Action Fund and CE Action Committee.

He was runner-up last time OpenSecrets Blog checked in on megadonors, when hedge funder Robert Mercer topped the list. But between June 28 and July 20, Steyer gave $14 million to NextGen Climate Action, doubling his total contributions and vaulting him into the lead among megadonors.

In the meantime, NextGen Climate Action raised the fifth largest amount of money for the 2016 election cycle to date, but has spent only $700,000 of its $38 million raised, all to advertise against Republicans, according to CRP data.

Trend or Anomaly?

While the level of outside spending, especially by super PACs, may seem astronomical to some, it doesn’t to others who have been watching the trend lines since the Supreme Court’s 2010 Citizens United decision. Total outside spending from August 2008 to August 2012 tripled, from $96.8 million to $289.3 million.

Holman is surprised the total from in the last four years has only doubled.

“I fully expect the numbers to soar three or even four times by the end of November,” Holman said.