A few of you asked some terrific questions in class on Monday concerning the breadth of the President's constitutional power to issue pardons. And, lo and behold, I think we have some answers.
The pardon power is set out in Article II, section 2, clause 1. It states that the President "shall have Power to grant Reprieves and Pardons for Offences against the United States, except in cases of Impeachment." One obvious limitation, which flows from both the text and our federal structure, is that the President cannot pardon persons from offenses against the states (that is, violations of state law). Another clear textual limitation is that the power does not extend to cases of impeachment.
Beyond that, there does not appear to be much by way of limits. There is no substantive limit as to what is a legitimate basis for granting a pardon. Thus, there is nothing that prevents the President, other than political forces, from granting pardons in cases where he has a clear conflict of interest (consider the cases of Casper Weinberger and Marc Rich).
Further, it includes the power to pardon whole classes of people simultaneously by proclamations of amnesty, see United States v. Klein, 80 U.S. 128, 147 (1871), and it can be exercised any time subsequent to the commission of the offense, even prior to indictment, see Ex parte Garland, 71 U.S. 333 (1866). Moreover, the pardon power cannot be "modified, abridged, or diminished by the Congress." Schick v. Reed, 419 U.S. 256, 266 (1974).
The President may not, however, pardon persons for acts that have not yet been committed. See L. Tribe, American Constitutional Law sec. 4-10, at p. 720 (3d ed. 2000). As some of you foresaw in our discussion Monday, such a power "would amount to a presidential arrogation of authority to dispense with the laws--and hence the rule of law--altogether." Id.