The Constitution is pretty simple.
"he shall have power to grant reprieves and pardons for offenses against the United States, except in cases of impeachment."
This doesn't mean that a pardon can take place only after conviction. So yes, A president can pardon himself.
In fact, raving leftists were hoping that Klintoon would do just that.
http://writ.news.findlaw.com/dean/20001208.html"While no president has ever pardoned himself, the law supports the president's authority to do so. Scholarly inquiry into the subject was provoked first by fear that Richard Nixon would pardon himself to escape Watergate; later by thought that George H. W. Bush would do so because of the Iran-Contra grand jury; and most recently by concern about Bill Clinton's problem of a possible post-Presidency indictment and trial. And while a few scholars have concluded that the president cannot pardon himself, many more believe that he can.
As one Member of Congress said during the Clinton impeachment proceedings, "the prevailing opinion is the President can pardon himself." Thus, should Bill Clinton pardon himself, and should Independent Counsel Ray decide to go to Court to test his presidential power to do so, not only would that court case delay the prospect of resolving any criminal action against the former president quickly, it would also present a case of first impression, with the authority overwhelmingly on the side of the former president.
The president's pardon power is set forth in the constitution. Article II, section 2 grants the president "Power to grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment." The text of the constitution, its history, and the placement of the pardon power within the structure of the constitution, all show that there are no limits on this power, other than the exception that prevents the president from pardoning "impeachments." Accordingly, the Supreme Court has described this presidential power as "plenary." As one recent commentator summed it up, short of a constitutional amendment, there is absolutely nothing "to prevent any president from pardoning himself."
Will Bill Clinton do so? We won't know until he is indicted, for he would have to plead it as his defense. I would assume that we will have an answer to this question by March, or by end of April at the latest — if Independent Counsel Ray proceeds as he has indicated. Although I cannot predict the answer, this much I can promise: it will be interesting. "
