A group of only 50 wealthy people (and their relatives) have donated nearly half of all the money that has gone into super PACS for the 2016 elections, The Washington Post reports. The 2,300 super PACs have received more than $607 million this election cycle, and the groups have no limit on contributions that they may accept. Donors will likely spend hundreds of millions more before the general election is over. So far, the biggest contributor has been former hedge fund manager and environmentalist Tom Steyer, a supporter of liberal causes. He donated $17 million to form a super PAC that supports candidates with a commitment to preventing climate change. Steyer reportedly spent $74 million during the 2014 elections, but he says he plans to surpass that amount this year.