WASHINGTON – OCTOBER 31: (AFP OUT) President Barack Obama and first lady Michelle Obama greet parents, trick-or-treaters and local school children at the north portico of the White House during a Halloween celebration on October 31, 2009 in Washington, DC. The Obamas are celebrating their first Halloween in the White House by inviting students and military families over for the holiday. (Photo by Kristoffer Tripplaar-Pool/Getty Images)