Paul McNulty resigned:

The No. 2 official at the Justice Department, Deputy Attorney General Paul McNulty, submitted his resignation to Attorney General Alberto Gonzales, the Justice Department announced Monday.

McNulty cited personal reasons for his resignation.

"The financial realities of college-age children and two decades of public service lead me to a long overdue transition in my career," he wrote in his resignation letter.

Or in Kyle Sampson speak, he resigned for performance reasons:

the distinction between "political" and "performance-related" reasons for removing a United States Attorney is, in my view, largely artificial. A U.S. Attorney who is unsuccessful from a political perspective, either because he or she has alienated the leadership of the Department in Washington or cannot work constructively with law enforcement or other governmental constituencies in the district important to effective leadership of the office, is unsuccessful.

This is a sad day for injustice.