Answer:
1. The U.S. Constitution gives the president the power to pardon under Article II, Section 2, which states that the president "shall have Power to grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment."
2. The Constitutional power granted to the president to pardon can be changed only through a constitutional amendment, which requires approval from two-thirds of both the House of Representatives and the Senate, as well as ratification by three-fourths of the states.
3. A pardon is an executive order by the president that forgives a person convicted of a federal crime, releasing the person from the punishment and consequences of the crime. A commutation is an executive order by the president that reduces or eliminates the sentence of a person convicted of a federal crime, but does not forgive the crime itself.
(Shorter response for 3): Pardon is the forgiveness of a crime and the cancellation of the penalty or punishment associated with it. Commutation is the reduction or lessening of a sentence for a crime, typically from a more severe to a less severe punishment.
4. The president cannot pardon someone for a state crime or civil liability, and cannot use the pardon power to obstruct justice or commit a crime. The pardon power is also subject to the limitation that it can only be used for federal crimes, and only after the person has been convicted of the crime.
5. The Department of Justice has a role in the pardon process, as it is responsible for reviewing and investigating pardon applications, making recommendations to the president, and preparing the final paperwork for the president's signature. However, the president has the final authority to grant or deny a pardon.
6. President George W. Bush pardoned 189 people and commuted the sentences of 11 people.
7. President George W. Bush commuted the sentence of Lewis "Scooter" Libby, who was convicted of obstruction of justice, perjury, and making false statements in connection with the investigation into the leak of a CIA agent's identity. He also commuted the sentences of Jose A. Compean and Ignacio Ramos, two border patrol agents who were convicted of shooting an unarmed suspect and covering up the incident.
8. President Obama pardoned 212 and commuted the sentence of 1705 people.
9. President Obama commuted the sentence of Chelsea Manning, who was convicted of violating the Espionage Act and other offenses for leaking classified documents to WikiLeaks. He also pardoned James Cartwright, a retired general who pleaded guilty to lying to the FBI during an investigation into the leaking of classified information about a secret cyberattack on Iran's nuclear program.
10. President Trump pardoned 237 and commuted the sentence of 94 people.
11. President Trump pardoned Joseph Arpaio, a former Arizona sheriff who was convicted of criminal contempt of court for disobeying a court order to stop racial profiling practices. He also pardoned Michael Flynn, his former national security advisor who pleaded guilty to lying to the FBI about his contacts with Russian officials during the 2016 election.
12. President Biden has not yet issued any pardons or commutations as of March 2023.
Hope this helps! Sorry if it doesn't. If you need more help, ask me! :]