John D. Ashcroft to President George W. Bush, November 2, 2004 [resigning from the office of US Attorney General; released November 9, 2004]. Excerpt:

The demands of justice are both rewarding and depleting. I take great personal satisfaction in the record which has been developed. The objective of securing the safety of Americans from crime and terror has been achieved. The rule of law has been strengthened and upheld in the courts. Yet, I believe that the Department of Justice would be well served by new leadership and fresh inspiration. I believe that my energies and talents should be directed toward other challenging horizons. Therefore, I humbly state my desire to resign from the office of United States Attorney General.

View a photocopy and read the full text here, via MSNBC. Reported in JURIST's Paper Chase here.