Where Billionaires Are Placing Bets In This Year's Elections

WASHINGTON -- As the Democratic Party works to hold control of the U.S. Senate for the final two years of Barack Obama's presidency, a key strategy for November's elections seeks to tie Republican challengers to policies advocated by billionaire donors, especially brothers Charles and David Koch.

In Iowa, for example, where Republican state Sen. Joni Ernst is running for the U.S. Senate seat now held by retiring Sen. Tom Harkin (D), a recent ad from Senate Majority PAC, a super PAC supporting Democrats, says Ernst backs the same policies as the Koch brothers, whose nonprofit organizations have spent big to boost her candidacy. "Follow the money," an announcer says. "It's the oldest rule in politics."

Following the money, while made more difficult by the rise of undisclosed dark moneyin this year's campaign, does indeed show that billionaires are spending big. An analysis by The Huffington Post of contributions made by the nation's approximately 471 billionaires and their families found that the wealthiest sector of American society has donated $113.7 million in races for federal offices.