Five years after the Supreme Court’s Citizens United decision helped unleash unprecedented amounts of outside spending in U.S. elections, a coalition of major pro-democracy groups came together for the first time on Wednesday to release eight separate reports examining outsized corporate influence, the proliferation of dark money, and the corrupting role of money in politics.

“There’s no denying it,” the clean elections group Public Campaign declared. “Big money in elections is getting bigger and the increased cost of elections is fueled by a shrinking handful of America’s wealthiest individuals.” 

Ian Vandewalker, who authored the Brennan Center for Justice’s report, said: “The post-Citizens United numbers paint a daunting picture: Outside money driven mostly by a few wealthy donors now surpasses even spending by candidates themselves in tight races, giving those donors a level of election influence unprecedented in modern American history. At the same time, the rise of dark-money and single-candidate groups threaten two longstanding cornerstones of money in politics regulation, transparency and contribution limits. Congress, the president, and federal agencies all should seize opportunities to make reforms improving transparency and boosting the power of small donors.”

The research was presented at a symposium in Washington, D.C. on Wednesday, ‘Five Years After Citizens United: A Joint Research Release.’

Citizens United and other recent court decisions have “opened the floodgates to big money influence in our democracy, giving special interests and the wealthy more control over our government and economy than they’ve enjoyed since the Gilded Age of the late 19th century,” reads the report (pdf) from Boston-based Common Cause.

In particular, the Common Cause study looks at five key issue areas—stagnant wages, gun control, climate change, student debt, and net neutrality—where “unfettered political spending and influence have blocked progress on solutions that large, bipartisan majorities of Americans support.”

According to Common Cause, Walmart alone and the U.S. Chamber of Commerce spent $14.8 million and $35 million respectively in 2014 advocating against raising the minimum wage, even while 70 percent of Americans support a national increase. The NRA spent more than $31.4 million in the last election cycle to drive off gun control reforms, even as 90 percent of citizens have expressed support for background checks. Similar data revealed that big money from the energy sector, major banks, and telecom industry have respectively blocked action on reducing carbon emissions, establishing refinancing plans for student debt relief, and efforts to keep the internet open for everyone.

Since 2010, outside spending on Senate elections has more than doubled, from $220 million that year to $486 million in 2014, Brennan Center report (pdf) reveals. On top of that, so called ‘dark money’—shadowy funding from undisclosed donors—has more than doubled since 2010, the year the Citizens United decision came down.

“The story that emerges is that outside spending has exploded in the last three federal elections and is highly focused on competitive races,” the analysis reads. “In 80 percent of competitive 2014 races, outside spenders outspent the candidates—sometimes by more than double. Because outside groups like super PACs and political nonprofits can take contributions of unlimited size, the increasing dominance of outside money is giving the wealthiest few Americans more and more control over the political process.”

The Brennan Center’s report also shows that 2014’s 11 competitive Senate races saw 16 candidate-specific groups spend more than $1 million each, more than double the number in 2012. These groups depend heavily on donors who have given up to the legal limit of $2,600 directly to their chosen candidate.

“These organizations take unlimited donations and spend the money exclusively in support of one candidate, making a mockery of longstanding contribution limits that guard against the danger of corruption through large contributions,” the report charges.

“There’s some good news,” the Public Campaign report (pdf) insists, turning its focus on state-level, broad ‘clean elections’ models that are still drawing in hundreds of candidates.

The non-profit’s analysis looks at three states—Arizona, Connecticut, and Maine—that currently offer grants to candidates who raise a minimum number of small, local donations. Nearly 300 officials elected in those states this fall benefited from such programs, with Connecticut leading the way.

In fact, the report says, “[s]ince 2010, Connecticut candidates have reduced their financial reliance on the wealthiest zip codes in the state and increased their reliance on donations from middle and low income areas.”

The Center’s report (pdf) zooms in even more, to examine how “[a] legitimate bipartisan effort to enforce Wisconsin’s long-standing campaign finance laws has been contorted beyond recognition into a ‘partisan witch hunt’ by a well-funded legal and media campaign.”