SELMA, AL - MARCH 04: (L to R) Democratic Presidential candidate Senator Barack Obama, Congressman John Lewis (D-GA), Democratic Presidential candidate Senator Hillary Clinton and her husband former president Bill Clinton march with a crowd to the Edmund Pettus Bridge to commemorate the 1965 "Bloody Sunday" Voting Rights march March 4, 2007 in Selma, Alabama. In the 1965 march which was to go from Selma to Montgomery, Alabama police used tear gas and beat back the marchers when they reached the Pettus Bridge.