Kim Barker and Theodoric Meyer Posts

Since the Supreme Court's 2010 Citizens United decision, conservative groups have far outspent their liberal counterparts. In the 2012 federal election cycle alone, conservatives shelled out almost two and a half times the amount of outside money as liberal groups, including labor unions. But an early look at spending on television ads in North Carolina, home to a hotly contested Senate race and a number of competitive state races, shows that liberals are asserting themselves as never before. They are spending almost as much as conservatives in the Senate race and pouring funds into state contests that conservatives haven't yet spent a cent on.

IRS official Lois Lerner has come under fire for targeting conservative groups before the 2012 elections. But she also targeted liberal and nonpartisan dark money groups as well, and it looks more like a problem an with overstressed, understaffed department than a nefarious plot to take down the tea party.

Libertarian billionaire brothers Charles and David Koch were among the first to grasp the political potential of social welfare groups and trade associations — nonprofits that can spend money to influence elections but don’t have to name their donors. The Kochs and their allies have built up a complex network of such organizations, which spent more than $383 million in the run-up to the 2012 election alone. It sounds complicated and arcane because it is.