US President Barack Obama and First Lady Michelle Obama walk to greet wellwishers at Cape Cod Air Force Station in Massachusetts on August 6, 2016 as they arrive for a two-week holiday at nearby Martha's Vineyard. / AFP / NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)
US President Barack Obama and First Lady Michelle Obama greet wellwishers at Cape Cod Air Force Station in Massachusetts on August 6, 2016 as they arrive for a two-week holiday at nearby Martha's Vineyard. / AFP / NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)
US President Barack Obama, First Lady Michelle Obama and daughters Malia(upperR) and Sasha step off Air Force One at Cape Cod Air Force Station in Massachusetts on August 6, 2016 as they arrive for a two-week holiday at nearby Martha's Vineyard. / AFP / NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)
US President Barack Obama, First Lady Michelle Obama and daughters Malia and Sasha(L) walk to board Air Force One at Andrews Air Force Base in Maryland on August 6, 2016 as they depart for a two-week holiday at Martha's Vineyard, Massachusetts. / AFP / NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)
US President Barack Obama and First Lady Michelle Obama greet wellwishers at Cape Cod Air Force Station in Massachusetts on August 6, 2016 as they arrive for a two-week holiday at nearby Martha's Vineyard. / AFP / NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)
