Bush still finds time to work on an autobiography, serve on the Boards of AmeriCares and the Mayo Clinic, and continue her prominent role in the Barbara Bush Foundation.

WHITEHOUSE: Barbara Pierce Bush

World Food Programme, Yele Haiti Foundation, and the Clinton Bush Haiti Foundation.

CNN: Telethon tries to raise 'Hope for Haiti'

Since Mr. Obama became president in 2009, the U.S. has conducted more than 300 drone strikes in Pakistan, compared with fewer than 50 during the presidency of George W. Bush, according to the nonpartisan New America Foundation.

WSJ: Obama Narrows Scope of Counterterrorism Fight

President Barack Obama has signed off on hundreds of strikes, nearly seven times the number President George W Bush authorised during his two terms, according to the Washington-based New America Foundation.

BBC: Viewpoint: US media lax on drones

Mr. Bush, the Republican governor of Florida from 1999 to 2007, is chairman of the Foundation for Excellence in Education.

WSJ: Jeb Bush and Clint Bolick: Solving the Immigration Puzzle