A Justice Department prosecutor defied his superiors by testifying at a U.S. Civil Rights Commission hearing Friday, where he leveled an explosive allegation: top officials in the department gutted a voter intimidation case against a fringe African American militant group because the suspects were black and their alleged victims were white. The prosecutor, Christopher Coates, also said the downgrading of the case against the New Black Panther Party was evidence of a Justice Department culture which discouraged “race neutral” enforcement of civil rights laws, frowned on prosecuting minority perpetrators and folded under pressure from black and Latino rights groups. After...