The U.S. Attorney position is one characterized by a broad delegation of the duty to enforce the laws of the United States, and to appear on behalf of the government in any civil action involving the United States or its revenues. This delegation of duties necessarily entails the exercise of discretion, and that exercise of discretion necessarily depends on the United States Attorneys' independence of judgment. The U.S. Attorney can thus be described as an agent with multiple principles, or a servant of two masters: the U.S. Attorneys clearly serve at the "pleasure" of the President, must be responsive to the Department of Justice, and must also consider local conditions, and yet the Attorneys' ultimate duty is to serve, advance, and enforce the law while ensuring uniform application of just principles.
Christian M. Halliburton, The Constitutional and Statutory Framework Organizing the Office of the United States Attorney, 31 SEATTLE U. L. REV. 213 (2007).