Vice President Joe Biden and Dr. Jill Biden visit with troops and their families on Christmas Day at Walter Reed Army Medical Center in Washington, D.C., Dec. 25, 2010.

Vice President Joe Biden and Dr. Jill Biden visit with troops and their families on Christmas Day at Walter Reed Army Medical Center in Washington, D.C., Dec. 25, 2010.

Vice President Joe Biden and Dr. Jill Biden visit with troops and their families on Christmas Day at Walter Reed Army Medical Center in Washington, D.C., Dec. 25, 2010.