A senior Republican on the Senate Judiciary Committee on Tuesday described as “inconceivable” a Justice Department decision to promote key Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) personnel who oversaw the controversial “Fast and Furious” weapons investigation that allowed hundreds of guns to be walked into Mexico to new positions in Washington.

Sen. John Cornyn of Texas, who last week demanded that Attorney General Eric H. Holder Jr. immediately brief his office regarding the “scope and details of any past or present ATF gun-walking programs” in his state, said until Mr. Holder and the department “come clean” on the gun-walking investigation, “it is inconceivable to reward those who spearheaded this disastrous operation with cushy desks in Washington.”