WASHINGTON (Reuters) - A US man pleaded guilty on Monday to charges of conspiring to carry out a killing spree targeting African Americans, including then-presidential candidate Barack Obama, the Justice Department said. Daniel Cowart, 21, of Bells, Tennessee, said he had plotted with Paul Schlesselman of West Helena, Arkansas to carry out a racially motivated plot to murder dozens of people. He said he had planned to culminate the attacks by assassinating Obama, then a US senator and presidential candidate. Despite great civil rights progress, this unthinkable conspiracy serves as a reminder that hate-fuelled violence remains all too common in our country, said Thomas Perez, assistant attorney general for the departments Civil Rights division. Under terms of a plea agreement, Cowart faces between 10 and 75 years in prison. Schlesselman pleaded guilty in January to three counts and faces 10 years in prison under a plea agreement.