Since the beginning of the presidency, US Presidents have claimed that the right to govern is the President's exclusive prerogative. Thus, any actions which the President deems necessary to accomplish the needs of the nation have been justified under this clause. Presidents have granted themselves emergency powers to accomplish the required tasks.
Presidents have taken the position throughout American history that they have the responsibility to govern and, thus, any and all actions necessary to do so, whether expressly authorized by the Constitution, are appropriate. The first debate in this arena took place when President Washington issued a Proclamation of Neutrality in the War between Great Britain and France. Jefferson argued that the President did not have the right to unilaterally issue a proclamation of neutrality. What then transpired was a series of letters between Hamilton, under the pen name Pacificus, supporting the President and Madison, under the pen name Helvidicus.
When Jefferson became President, he ignored his own limited view of the presidency by negotiating the Louisiana Purchase himself, a power that was not stated explicitly in the Constitution. Jefferson also went on to spend, unilaterally, unappropriated funds to restock military supplies after the British had attacked the USS Chesapeake. The greatest use of emergency powers was by President Lincoln during the Civil War. He abrogated private property when he freed the slaves and he unilaterally abrogated habeas corpus. President Theodore Roosevelt believed in an expansionist view of the president's powers, believing he had a stewardship of the American people to accomplish whatever he felt was needed. President Franklin Roosevelt, Teddy Roosevelt's cousin, furthered the view of stewardship during the days of World War II when he claimed emergency powers. President Nixon claimed emergency powers to justify his ordering federal intelligence agencies to illegally conduct surveillance on Americans during the early 1970's. These actions were listed under one of the Articles of Impeachment against him.
Although the Supreme Court has generally gone along with emergency powers, it did strike down the use of military courts to try civilians during the Civil War in the case of Ex Parte Milligan. In the case of In re Neagle, the Court upheld the power of the President to assign a marshal to guard a Supreme Court justice. The Court stated: "In the view we take of the Constitution of the United States, any obligation fairly and properly inferable from that instrument, or any duty of the marshal to be derived from the general scope of his duties under the laws of the United States, is 'a law' within the meaning of the phrase."
In 1895, in the case of In re Debs, the Supreme Court upheld the constitutionality of an injunction which President Grover Cleveland obtained against Eugene Debs, organizer of the massive Pullman strike of 1894. In the cases of Hirabayshi v. United States and Korematsu v. United States, the court affirmed the President's emergency powers to deport Japanese-Americans. The Court did, however, limit the emergency powers of the president when it overturned the seizure of the steel mills by President Truman during the Korean War.