Attorney General Alberto Gonzales has finally done something important to advance the cause of justice. He has resigned. But his departure alone cannot remove the dark cloud that hangs over the Justice Department. President Bush needs to choose a new attorney general of unquestioned integrity who would work to make the department worthy of its name again — and provide the mandate to do it. Congress needs to continue to investigate the many scandals Mr. Gonzales leaves behind.

When Mr. Gonzales was appointed, it seemed doubtful that he would be able to put aside his years as Mr. Bush’s personal lawyer, which stretched back to the Texas governor’s office, and represent the interests of the American people. He never did.