Click here for more from Mother Jones.
Here is an excerpt from that piece:
In an interview with Mother Jones, Rep. Chris Van Hollen (D-Md.), the past chairman of the Democratic Congressional Campaign Committee and one of Congress' staunchest campaign-finance reform advocates, says Democrats and left-leaning groups are mulling a legal fight that would challenge the tax-exempt status of independent right-wing groups that sprung up in the aftermath of the Citizens United decision. Their targets include groups such as Karl Rove's Crossroads GPS and the American Action Network (AAN), run by former GOP Minnesota Sen. Norm Coleman, which together spent more than $43 million supporting conservative candidates and attacking Democratic ones, making up 23 percent of all outside conservative spending. "People are looking at different legal strategies through the courts because there's emerging evidence that these groups have abused the rules," Van Hollen says.