Presidential hopeful Sen. Barack Obama, D-Ill., arrives for a speech at Prince Georges Community College Wednesday, October 10, 2007 in Largo, Md. (AP Photo/Evan Vucci)
Presidential hopeful Sen. Barack Obama, D-Ill., right, walks to make a campaign speech with the Frederick Douglas High School marching band at the Prince Georges Community College Wednesday, October 10, 2007 in Largo, Md. (AP Photo/Evan Vucci)
Presidential hopeful Sen. Barack Obama, D-Ill., pauses during a speech at Prince Georges Community College Wednesday, October 10, 2007 in Largo, Md. (AP Photo/Evan Vucci)
Presidential hopeful Sen. Barack Obama, D-Ill., speaks at Prince Georges Community College Wednesday, October 10, 2007 in Largo, Md. (AP Photo/Evan Vucci)
The shadow of presidential hopeful Sen. Barack Obama, D-Ill., is reflected on a flag during a speech at Prince Georges Community College Wednesday, October 10, 2007 in Largo, Md. (AP Photo/Evan Vucci)