U.S. President Barack Obama receives a child dressed as the Pope Francis on the South Lawn of the White House during a Halloween trick-or-treating celebration in Washington October 30, 2015. Invitees included local children and the children of military families, according to the White House. REUTERS/Carlos Barria TPX IMAGES OF THE DAY

U.S. President Barack Obama smiles at a child during a Halloween trick-or-treating celebration on the South Lawn of the White House in Washington October 30, 2015. REUTERS/Carlos Barria 

U.S. President Barack Obama uses a magnifying glass to play a game with children in a pre-kindergarten classroom at College Heights early childhood learning center in Decatur February 14, 2013. REUTERS/Jason Reed 

U.S. President Barack Obama touches the cheek of Akira Cooper during a visit to the Community Children's Center in Lawrence, Kansas January 22, 2015. REUTERS/Kevin Lamarque 

U.S. President Barack Obama dances with entertainers during the National Christmas Tree Lighting ceremony on the Ellipse in Washington December 6, 2013. REUTERS/Kevin Lamarque 

U.S. President Barack Obama holds a pair of toddlers as he greets fans at halftime of an NBA opening night game between the Cleveland Cavaliers and the Chicago Bulls in Chicago October 27, 2015. Earlier Tuesday Obama delivered remarks at an International Association of Chiefs of Police (IACP) conference and attended Democratic Party events in Chicago. REUTERS/Jonathan Ernst 

U.S. President Barack Obama shares his strawberry pie with a boy during a lunch stop at the Kozy Corners restaurant in Oak Harbor, Ohio,July 5, 2012. REUTERS/Pete Souza/White House/Handout 

U.S. President Barack Obama reacts as Joey Hudy of Phoenix, Arizona, launches a marshmallow from his Extreme Marshmallow Cannon during the second White House Science Fair in Washington February 7, 2012. REUTERS/Kevin Lamarque 

U.S. President Barack Obama picks up four-year old Candace Rosemary O' Donnell after speaking at a town hall meeting on health insurance reform at Portsmouth High School in Portsmouth, New Hampshire, August 11, 2009. REUTERS/Jim Young (UNITED STATES POLITICS HEALTH) 

U.S. President Barack Obama high-fives eight-year-old Hinna Zejah after unveiling a series of gun control proposals during an event at the White House in Washington, January 16, 2013. REUTERS/Jason Reed 

U.S. President Barack Obama tries to evade the wandering fingers of 8-month-old Cooper Wall Wagner as he met U.S. Marines and their families at Kaneohe Bay Marine Corps base in Hawaii, December 25, 2011. REUTERS/Jason Reed 

U.S. President Barack Obama touches the spiked hair style of a child while visiting the Clarence Tinker elementary school children while at MacDill Air Force Base in Tampa, Florida, September 17, 2014. REUTERS/Larry Downing (UNITED STATES - Tags: POLITICS MILITARY EDUCATION TPX IMAGES OF THE DAY) 

Children from public schools in the town of Chatfield, Minnesota, help U.S. President Barack Obama get up after he posed with them for a picture, during his bus trip to the Midwest August 15, 2011. REUTERS/Jason Reed 

U.S. President Barack Obama talks with a pre-kindergarten student at Moravia Park Elementary School during his second 'Middle Class Jobs and Opportunity Tour' in Baltimore, Maryland May 17, 2013. REUTERS/Kevin Lamarque ( 

U.S. President Barack Obama gets a hug from a boy upon his arrival in Newark, New Jersey September 4, 2011. Obama was in New Jersey to tour damage caused by the rain-swollen Passaic River in the aftermath of Hurricane Irene.
REUTERS/Kevin Lamarque (UNITED STATES - Tags: POLITICS TPX IMAGES OF THE DAY SOCIETY ENVIRONMENT) 

Girls hug U.S. President Barack Obama as he visits the Boys and Girls Club of Cleveland, Broadway section, in Cleveland, Ohio June 14, 2012.

REUTERS/Kevin Lamarque (UNITED STATES - Tags: ELECTIONS POLITICS TPX IMAGES OF THE DAY) 

U.S. President Barack Obama picks up a boy to help him shoot a basketball as part of the Annual Easter Egg Roll on the South Lawn at the White House in Washington, April 13, 2009. REUTERS/Jim Young (UNITED STATES POLITICS SOCIETY)