The Congress, whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution, or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as part of this Constitution, when ratified by the Legislatures of three fourths of the several States, or by Conventions in three fourths thereof, as the one or the other Mode of Ratification may be proposed by the Congress; Provided that no Amendment which may be made prior to the Year One thousand eight hundred and eight shall in any Manner affect the first and fourth Clauses in the Ninth Section of the first Article; and that no State, without its Consent, shall be deprived of its equal Suffrage in the Senate.
It seems to me that President Bush, and the Republican Party have demonstrated, rather clearly, the need to put limits of the Presidential Power of the Pardon - not only did they pardon Libby for obstructing an investigation, but they have been commenting rather forcefully about the advantages of forestalling any future investigations by preemptively pardoning their fellow travelers rather than allowing the peasants their day in court.
So it seems to me to be reasonable to consider whether it's worth limiting this absolute privilege of the executive with a set of amendments.
28th Amendment (Proposed):
No pardon or clemency shall be issued prior to a finding of guilt for a crime by the judiciary, all such pardons shall be issued publicly, detailing in full the act or acts for which the pardon or clemency was granted.29th Amendment (Proposed):
No pardon or clemency for any act obstructing an investigation of another criminal act, whether by perjury or other means, shall be issued.
30th Amendment (Proposed):
Neither the President, Vice President, President pre tempore of the Senate, Speaker of the House of Representatives, any Justice of the Supreme Court, nor any Officer of the Executive appointed with the advice and consent of the Senate shall be eligible for pardon or clemency for any crime performed while in office.