Democratic presidential hopeful, Sen. Barack Obama, D-Ill. , left, accompanied by staff member Nicholas Colvin, right, and a member of his security detail,  walks on Capitol Hill in Washington, Wednesday, Feb. 6, 2008, after voting on an amendment to the Foreign Intelligence Surveillance Act (FISA). AP Photo logo AP Photo 52 months ago

Democratic presidential hopeful, Sen. Barack Obama, D-Ill. , left, accompanied by staff member Nicholas Colvin, right, and a member of his security detail, walks on Capitol Hill in Washington, Wednesday, Feb. 6, 2008, after voting on an amendment to the Foreign Intelligence Surveillance Act (FISA).