From left, former British Prime Minister Tony Blair, former Secretary of State Condoleezza Rice, former Vice President Dick Cheney, and former President George W. Bush's daughter Jenna Bush Hager, participate in the singing of "God Bless America" at the dedication of the George W. Bush presidential library on the campus of Southern Methodist University in Dallas, Thursday, April 25, 2013. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

From left, former British Prime Minister Tony Blair, former Secretary of State Condoleezza Rice, former Vice President Dick Cheney, and former President George W. Bush's daughter Jenna Bush Hager, participate in the singing of "God Bless America" at the dedication of the George W. Bush presidential library on the campus of Southern Methodist University in Dallas, Thursday, April 25, 2013. (AP Photo/Charles Dharapak)