With the election of 2016 shaping up to be the most expensive in U.S. history, candidates from both political parties are relying on the generosity of big donors to get their message out to the American people. With more money pouring into campaign coffers than ever before, a collective cry has been raised to curtail the spending of individuals and special-interest groups capable of raising billions of dollars for a single campaign. Who are the high rollers contributing to presidential candidates and why are they're giving so much of their money away? In search of answers, Alexandra Pelosi takes viewers behind the scenes to top-dollar fundraisers -- and chats with dozens of ultra-rich mega-donors.