A study by the US non-profit investigative journalism firm ProPublica has revealed that the share of campaign financing gathered for local and state elections from a single donor has quadrupled between 2012 and 2014, predicting that the worrying trend is only set to worsen in 2016.

The Super Political Action Committee (or Super PAC), a form of campaign financing capable of gathering virtually unlimited donations to support a candidate or cause, originated in 2010, when the Supreme Court abolished limitations on campaign contributions by individuals, while simultaneously allowing corporations, unions, and other groups to make virtually unlimited contributions, turning wealthy donors into potential political power players overnight.

ProPublica's study has found that since the Supreme Court ruling, Super PACs have seen not only a vast increase in big money donations, but also a skyrocketing in donations dominated by a single source. The group has found that in 2014, 59 Super PACs contributing a total of $113 million, or 16 percent of all Super PAC financing that year, were dominated by a single individual or group (to the tune of 80 percent or more). This amounts to over four times the $33 million such groups raised in 2012.

ProPublica journalists Robert Faturechi and Jonathan Stray are worried that the rapid growth of single-donor influence "is a new example of how changes in campaign finance law are giving outsized influence to a handful of funders," noting that the wealthiest of Americans can now effectively "[wall] off their political contributions from other big and small players." Making clear that PACs on the whole are a playground for the rich, the journalists point out that six-figure donations amounted to nearly half of all PAC money raised over the past two election cycles.

Faturechi and Stray argue that this worrying trend of political power being concentrated in the hands of the economic elite is only set to worsen in 2016, citing a recent report in the semi-monthly National Review, which noted that Texas Senator Ted Cruz's campaign for the Republican presidential nomination would be supported by at least four separate Super PACs, each of them controlled by a single donor.

Hey, who needs one Super PAC when you can have four? @peteroverby reports on how Super PACs have grown up http://t.co/CMYTJemZot — Domenico Montanaro (@DomenicoNPR) 13 апреля 2015

The Super PAC system arising following the Supreme Court ruling on Citizens United in 2010 has been criticized by opponents of the overt fusion of big money with political influence ever since. Between 2011 and 2012, US political satirist Stephen Colbert won a Peabody Award for making an outright mockery of the Super PAC system with his "Americans for A Better Tomorrow, Tomorrow" Super PAC, pointing out the system's loopholes, and the fundamental threat the organizations pose to American democracy.

ProPublica's list of top single-donor PACs between 2012 and 2014 can be found here.