These words, 'necessary and proper,' in such an instrument, are probably to be considered as synonymous. Necessarily, powers must here intend such powers as are suitable and fitted to the object; such as are best and most useful in relation to the end proposed. If this be not so, and if congress could use no means but such as were absolutely indispensable to the existence of a granted power, the government would hardly exist; at least, it would be wholly inadequate to the purposes of its formation. 17 U.S. 316, 324-325.
Furthermore, the Court firmly established the supremacy of the Federal government, by determining that state action could not impede the Federal government's valid exercise of power. The Court determined that:
The constitution, therefore, declares, that the constitution itself, and the laws passed in pursuance of its provisions, shall be the supreme law of the land, and shall control all state legislation and state constitutions, which may be incompatible therewith; and it confides to this court the ultimate power of deciding all questions arising under the constitution and laws of the United States. The laws of the United States, then, made in pursuance of the constitution, are to be the supreme law of the land, anything in the laws of any state to the contrary notwithstanding. 17 U.S. 316, 326-327.
Even recently, the Court has been willing to recognize the breadth of the Executive branch's powers. In Dames & Moore v. Regan, 453 U.S. 654 (1981), the Court determined once Congress has delegated power to the Executive branch, the Executive has broad authority to act under that scope. Furthermore, the Court approved the suspension of claims filed in U.S. Courts, despite the fact that there was no statute authorizing such a suspension. As a result, the Court basically stated that the President's authority could be virtually unlimited, given the appropriate circumstances and a grant of Congressional authorization. There is a presumption that the President is acting pursuant to Congress' consent. Furthermore, the President has the power to enter into executive agreements with or without Congressional authorization.
However, there are concerns that the failure by the Supreme Court or Congress to interfere with the Executive's actions in the current war may be resulting in the abrogation of constitutional protections. There are concerns that the Bush Administration's action in denying civilians access to civilian courts and forcing them to make their claims in military tribunals has expanded the President's power in an unconstitutional manner. (ACSBlog). However, the fact is that the Supreme Court has taken steps to end the administration's unilateral abrogation of constitutional protections. In a case about Guantanamo detainees, the entire Supreme Court:
rejected Bush's claim that Congress and the courts could play no role in reviewing the legality of Guantanamo detentions. In the Hamdi case, Sandra Day O'Connor wrote for the majority that "whatever power the United States Constitution envisions for the Executive in its exchanges with other nations or with enemy organizations in times of conflict, it most assuredly envisions a role for all three branches when individual liberties are at stake." And in August 2006, a federal court declared the NSA spying program unconstitutional, rejecting the president's assertion of uncheckable authority with the stern warning that "there are no hereditary Kings in America." (Cole).
In addition, the Court differentiates between a President acting in his official capacity, and acts by a President outside of his official capacity. In Clinton v. Jones, 520 U.S. 681 (1997), the Court determined that even an acting President did not have immunity from liability for non-official acts done before attaining his role as President. On the contrary, it determined that a President would generally not be immune to private actions against a President under the separation of powers doctrine. The doctrine was established to safeguard against encroachment by one branch onto another, not to place any member of the Executive or Legislative branch beyond the scope of the law during the course of their time in office.
ACSBlog. "Issue Brief: 'A Call to Protect Civilian Justice: Beware the Creep of Military
Tribunals." Separation of Powers. 2008. ACSBlog. 19 Mar. 2008 http://www.acsblog.org/cat-separation-of-powers.html.
Clinton v. Jones, 520 U.S. 681 (1997).
Cole, David. "The Constitution." Harper's Magazine. 2007. The Harper's Magazine
Foundation. 19 Mar. 2008 http://www.harpers.org/archive/2007/06/0081546.