Groups backed by secret donors take the lead in shaping 2016 elections

The latest television ad touting GOP presidential contender Marco Rubio proclaims that he is “leading the fight” to stop President Obama’s nuclear deal with Iran. But the new spot, which hits the airwaves Wednesday, is not the work of his official campaign or even his allied super PAC.
Source: Groups backed by secret donors take the lead in shaping 2016 elections