- A presidential pardon is for federal crimes. The president cannot pardon someone for a state crime (or a crime committed subject to a local jurisdiction whose power is derived from a state).
- Presidential pardons are reinforced by the constitutional prohibitions against double jeopardy and ex post facto laws. Once a person has been pardoned for a federal crime, the federal government (and any territories or districts that derive their power from the federal government) cannot re-try the pardonee for that crime.
As pointed by another person in the same thread which really answers your question:
- Fourth major benefit of pardons: Presidential pardons are about checks and balances. The legislative system has determined a law, the judicial system has determined an infraction of that law, and with a pardon the presidential system can react to a mistake made by either the legislative or judicial branch.
http://politics.stackexchange.com/questions/7674/why-is-the-...
Some of the finer points:
- A presidential pardon is for federal crimes. The president cannot pardon someone for a state crime (or a crime committed subject to a local jurisdiction whose power is derived from a state).
- Presidential pardons are reinforced by the constitutional prohibitions against double jeopardy and ex post facto laws. Once a person has been pardoned for a federal crime, the federal government (and any territories or districts that derive their power from the federal government) cannot re-try the pardonee for that crime.
As pointed by another person in the same thread which really answers your question:
- Fourth major benefit of pardons: Presidential pardons are about checks and balances. The legislative system has determined a law, the judicial system has determined an infraction of that law, and with a pardon the presidential system can react to a mistake made by either the legislative or judicial branch.