Then-Secretary of State Hillary Clinton and Vice President Biden at a White House event in October 2011. A new book says President Obama's aides were then studying whether to replace Biden with the former first lady on the 2012 ticket. Kevin Dietsch /UPI /Landov hide caption

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George Soros, seen at a forum in Berlin last year, joined a superPAC backing a Hillary Clinton presidential run in 2016. Sean Gallup/Getty Images hide caption

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Hilary Clinton at last week's Clinton Global Initiative forum in in New York City. /PA Photos/Landov hide caption

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During the 2012 campaign cycle, CNN was among several news networks that hosted Republican debates. Now, the GOP says it doesn't want to be on either that network or NBC. Joe Raedle/Getty Images hide caption

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Former Secretary of State Hillary Clinton appears at the Women in Public Service Project leadership symposium in Bryn Mawr, Pa., on July 9. Matt Rourke/AP hide caption

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Secretary of State Hillary Clinton at a town hall meeting on Tuesday in Washington, D.C. She officially leaves her post on Friday. Mandel Ngan/AFP/Getty Images hide caption

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