Hillary Clinton speaks to the media after keynoting a Women's Empowerment Event at the United Nations on Tuesday in New York City. Clinton answered questions about recent allegations of an improperly used email account during her tenure as secretary of state. Yana Paskova/Getty Images hide caption

itoggle caption Yana Paskova/Getty Images

Former Secretary of State Hillary Clinton receives the Liberty Medal in 2013 from the National Constitution Center. Former Florida Gov. Jeb Bush was the group's honorary chairman. Both are now likely presidential candidates for their respective party's nomination. William Thomas Cain/Getty Images hide caption

itoggle caption William Thomas Cain/Getty Images

Former Secretary of State Hillary Clinton speaks to reporters Tuesday at United Nations headquarters, where she said she chose to use a personal email account for government business out of convenience. Seth Wenig/AP hide caption

itoggle caption Seth Wenig/AP

U.N. Secretary-General Ban Ki-Moon (in white-and-blue vest) joins other leaders at the 2015 International Women's Day March at Dag Hammarskjold Plaza on March 8 in New York City. Michael Stewart/WireImage/Getty Images hide caption

itoggle caption Michael Stewart/WireImage/Getty Images

U.S. Secretary of State Hillary Rodham Clinton checks her mobile phone in March 2012 after her address to the Security Council at United Nations headquarters. While she's asked the State Department to quickly release her emails from her tenure as secretary, the process likely will take months — dragging out media coverage and critical questions. Richard Drew/AP hide caption

itoggle caption Richard Drew/AP

Former Secretary of State Hillary Clinton, seen here at a U.N. event last March, has been criticized for using a private email account to conduct official business during her four years in the Obama administration. Andrew Burton/Getty Images hide caption

itoggle caption Andrew Burton/Getty Images

Former President George W. Bush (right) and his father, former President George H.W. Bush, wave as they leave a family wedding in Washington, D.C., in May 2006. Normand Blouin-Pool/Getty Images hide caption

itoggle caption Normand Blouin-Pool/Getty Images

Chelsea Clinton, vice chair of the Clinton Foundation, walks on stage Sept. 23 while moderating the panel discussion "Valuing What Matters" during the Clinton Global Initiative in New York. She gave birth to a baby girl, her first child, three days later. Mark Lennihan/AP hide caption

itoggle caption Mark Lennihan/AP

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

itoggle caption Andrew Burton/Getty Images

Rubio, seen here addressing the National Press Club in May, told NPR he'll decide on a presidential run in the next few months Alex Wong/Getty hide caption

itoggle caption Alex Wong/Getty

Before talking about the situation in Iraq, President Obama bantered with (from left to right) Senate Minority Leader Mitch McConnell, House Speaker John Boehner, Senate Majority Leader Harry Reid and House Minority Leader Nancy Pelosi. Pablo Martinez Monsivais/AP hide caption

itoggle caption Pablo Martinez Monsivais/AP

Hillary Clinton promotes her new book, Hard Choices, in Chicago on Wednesday. The former senator and secretary of state had a lively and much-talked-about chat this week with Fresh Air's Terry Gross. Stacy Thacker/AP hide caption

itoggle caption Stacy Thacker/AP

Hillary Clinton at a book signing in New York. The former secretary of state has said that Benghazi joins a long list of tragedies during administrations of both parties. Bebeto Matthews/AP hide caption

itoggle caption Bebeto Matthews/AP

Hillary Clinton poses for a family photo with former President Bill Clinton, daughter Chelsea, and son-in-law Marc Mezvinsky, after attending Chelsea's Oxford University graduation ceremony last month. Matt Dunham/AP hide caption

itoggle caption Matt Dunham/AP