Former Secretary of State Hillary Clinton speaks to a crowd during a book signing for her new book, Hard Choices. Clinton's book tour has brought her before admiring audiences, but also highlighted her difficulty talking about her wealth and her presidential vision. Andrew Burton/Getty Images hide caption

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The RNC wants to see many fewer of these presidential debate scenes in 2016. Before a November 2011 Michigan showdown, from left: former Pennsylvania Sen. Rick Santorum; Minnesota Rep. Michele Bachmann; former House Speaker Newt Gingrich; former Massachusetts Gov. Mitt Romney; businessman Herman Cain; Texas Gov. Rick Perry; Texas Rep. Ron Paul; former Utah Gov. Jon Huntsman. Paul Sancya/AP hide caption

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Republican presidential candidate Mitt Romney and vice presidential candidate Paul Ryan on stage with their wives Ann Romney and Janna Ryan at the Republican National Convention on Aug. 30. Jae C. Hong/AP hide caption

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Vermont Sen. Bernie Sanders, an independent, speaks during a December 2012 news conference on Capitol Hill. Sanders said recently he'd consider running for president if no other progressive candidate steps up. Jacquelyn Martin/AP hide caption

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Sen. Marco Rubio, R-Fla, is among a bipartisan group of eight senators who this week announced a plan to overhaul the nation's immigration laws. Charlie Neibergall/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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Secretary of State Hillary Clinton watches a video about her public life that was played before she addressed the Saban Forum in Washington last week. Mary Calvert/Reuters /Landov hide caption

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