https://www.commondreams.org/news/2018/09/13/citizens-united-just-15-groups-account-75-percent-800-million-dark-money-spent-us
"While the groups examined by Issue One have supported both Democrat and Republican candidates at various levels of politics, the only ones to break $100 million primarily back the GOP. The U.S. Chamber of Commerce—which gets substantial funding from big banks, pharmaceutical companies, and polluting industries—spent $130 million, and Crossroads GPS, co-founded by former White House strategist Karl Rove, spent $110 million. The third highest spender was the right-wing billionaire Koch Brothers' Americans for Prosperity."
