The rise of the super PAC has been one of the defining trends of the 2012 election. These non-campaign organizations which, thanks in part to the Supreme Court’s 2010 Citizens United decision, can raise and spend unlimited amounts influencing elections have had a staggering impact on how candidates and campaigns get their messages to voters. Case in point, new analysis from election law scholar Rick Hasen in Slate.

Hasen plotted the growth spending on elections over time by outside groups, which before 2010, meant mainly “527 organizations” – advocacy groups, whose name comes from part of the tax code, which were able to campaign on behalf of issues but not for or against specific candidates. As Hasen points out, some people have claimed that Citizens United isn’t important because 527s aren’t really all that different from super PACs. But the numbers don’t lie. Super PACs are having an enormous effect on the political process:

This chart shows that the total outside spending up to March 8 in 1992 was about $1.5 million. By March 8, 2008 that number was $37.5 million. This year: more than $88 million. That means in 2012, spending by non-campaign organizations is 234 percent of what it was in 2008.

Making things worse, while super PACs are supposed to disclose their donors, many use loopholes to obscure who is giving them money:

Further, lots of groups are now using 501(c) organizations rather than super PACs for their campaign spending, in an effort to hide their donors. A Center for Responsive Politics study found that in 2010 the percentage of “spending coming from groups that did not disclose their donors rose from 1 percent to 47 percent since the 2006 midterm elections,” and “501(c) non-profit spending increased from 0 percent of total spending by outside groups in 2006 to 42 percent in 2010.”

Okay, so outside groups are spending a lot more on this election than they have in past years. But surprisingly, the Republican primaries are also “shaping up as the cheapest and most financially depressed presidential nominating contests in years,” according to the Washington Post. The Republican candidates have raised and spent about half as much as they did in 2008, even including super PACs.

Explanations for this strange dichotomy abound: the poor economy, the extended primary season, and, most notably, the lack of enthusiasm for the candidates among donors:

David Donnelly, executive director of the Public Campaign Action Fund, which favors public financing of campaigns, noted that weak fundraising by candidates has served to amplify the impact of super PACs, which would have had much less influence if they had existed in 2008.

“There seems to be very little excitement among voters in the donor class about these candidates,” Donnelly said. “What that gets replaced with is this new phenomenon of people writing huge checks in support of the candidates. You’re replacing excitement with those who have a huge amount of money.” 

What’s scarier than the increasing ability of anonymous super-rich people to influence elections? That, accompanied by a decrease in enthusiasm from regular voters.