system
Given the following post, respond as if you're commenting on Reddit:
human
Does the US president have the authority to pardon/commute *all* prison sentences?

Let's say Obama is having a good day and decides he wants to pardon all US inmates. Could he do it? Are there checks from the legislative or judicial branches that could block him?
gpt
Presidents have issued pardons in large quantities before. Theodore Roosevelt pardoned everyone who took part in the rebellion the Philippines. Andrew Johnson pardoned all Confederate soldiers.

The president can only pardon federal crimes. He or she cannot pardon those convicted of offenses against state laws.