President Barack Obama, left, and former President George W. Bush sing the national anthem after Obama was sworn in to office January 20, 2009 (AP)

President Barack Obama, left, and former President George W. Bush sing the national anthem after Obama was sworn in to office January 20, 2009

President Barack Obama, left, and former President George W. Bush sing the national anthem after Obama was sworn in to office January 20, 2009 (AP)