<P> Harry Truman declared the use of emergency powers when he nationalized private steel mills that failed to produce steel because of a labor strike in 1952 . With the Korean War ongoing, Truman asserted that he could not wage war successfully if the economy failed to provide him with the material resources necessary to keep the troops well - equipped . The U.S. Supreme Court, however, refused to accept that argument in Youngstown Sheet & Tube Co. v. Sawyer, voting 6 - 3 that neither Commander in Chief powers nor any claimed emergency powers gave the president the authority to unilaterally seize private property without Congressional legislation . </P> <P> Executive privilege gives the president the ability to withhold information from the public, Congress, and the courts in national security and diplomatic affairs . George Washington first claimed privilege when Congress requested to see Chief Justice John Jay's notes from an unpopular treaty negotiation with Great Britain . While not enshrined in the Constitution, Washington's action created the precedent for privilege . When Richard Nixon tried to use executive privilege as a reason for not turning over subpoenaed audio tapes to a special prosecutor in the Watergate scandal, the Supreme Court ruled in United States v. Nixon that privilege was not absolute . The Court reasoned that the judiciary's interest in the "fair administration of criminal justice" outweighed President Nixon's interest in keeping the evidence secret . Later President Bill Clinton lost in federal court when he tried to assert privilege in the Lewinsky affair . The Supreme Court affirmed this in Clinton v. Jones, which denied the use of privilege in cases of civil suits . </P> <P> Because of the vast array of presidential roles and responsibilities, coupled with a conspicuous presence on the national and international scene, political analysts have tended to place great emphasis on the president's powers . Some have even spoken of "the imperial presidency", referring to the expanded role of the office that Franklin D. Roosevelt maintained during his term . </P> <P> President Theodore Roosevelt famously called the presidency a "bully pulpit" from which to raise issues nationally, for when a president raises an issue, it inevitably becomes subject to public debate . A president's power and influence may be limited, but politically the president is certainly the most important power in Washington and, furthermore, is one of the most famous and influential of all Americans . </P>

Where do the presidential powers come from and why