Republican Strategist Karl Rove

Republican Strategist Karl Rove

Brendan Smialowski/AFP via Getty Images

Nonprofits such as Priorities USA, founded by former aides to President Barack Obama, and Crossroads GPS, created with the help of Republican strategist Karl Rove, pictured, proliferated since the U.S. Supreme Court’s 2010 Citizens United decision that removed contribution limits on corporations and union giving to independent groups.