Read text of Deputy Attorney General Paul McNulty's resignation letter here.
[Late Update: Not to butt in, Clara, but I want to make one point: Gonzales has repeatedly said in congressional testimony that the advice/recommendations of his senior staff guided the U.S. Attorneys purge, not Gonzales' own thinking. Senior staff means McNulty, even if he's been more forthcoming than most, and even though Kyle Sampson seems more responsible for the purge. I think McNulty's resignation was inevitable. The only question now is whether enough heads have rolled to take pressure off Gonzo. -- Jonathan]