President Barack Obama, First Lady Michelle Obama, Vice President Joe Biden, Dr. Jill Biden, and their families attend an inaugural prayer service at St. John's Church in Washington, D.C., Jan. 21, 2013. (Official White House Photo by Pete Souza)

President Barack Obama, First Lady Michelle Obama, Vice President Joe Biden, Dr. Jill Biden, and their families attend an inaugural prayer service at St. John's Church in Washington, D.C., Jan. 21, 2013. (Official White House Photo by Pete Souza)