Super PACs have been lauded as the ultimate game changers this election season, but ProPublica's Kim Barker points us to their often-ignored cousins, social welfare nonprofit groups, otherwise known as 501(c)(4)s, and how they're bankrolling the campaigns. These nonprofits have already spent more than $71 million on TV ads mentioning a candidate for president, more than all super PACs combined, according to estimates from Kantar Media's Campaign Media Analysis Group. They continue to use questionable tactics to pour dark money into elections.

Barker joins us in the podcast studio this week to discuss how these 501(c)(4)s are underreporting their political activity to the IRS and why that matters. Ultimately, she asks, "Are we OK, as a democracy, with having all this anonymous money coming in?"

You can read Barker's report, How Nonprofits Spend Millions on Elections and Call It Public Welfare, check out the corresponding news app, and more on our Campaign 2012 series page. You can also listen to this podcast on Stitcher and iTunes.