As an outsider to US way of doing things I find allowing politicians to have ability to pardon criminals as totally, utterly bizarre. I can’t see how anyone can find it acceptable...especially towards end of a politicians tenure when he (or she) can not be held accountable by the electorate.
It’s up to a judge and jury to decide whether guilty or not, for the judge to decide appropriate sentence. After that it’s up to an appropriate parole board to decide if criminal can safely be released early...and that board should be solely concerned if early release will compromise public safety.
If anyone is pardoned, it should be because facts have emerged that make the original conviction unsafe...and that should be decided by judges (or jury guided by judges), not left to a politicians whim.
In general terms...in USA the legal system seems (by UK standards) to be directly influenced by politicians to an almost shocking extent. Have any of your politicians ever put case for making legal process more independent?