Why Trump commuted Stone's sentence

Why Trump Commuted Stone’s Sentence Instead of Pardoning Him.

...The brand of clemency Trump used here is a bit of a tell. Rather than pardoning Stone, Trump ordered a commutation, which means that Stone’s conviction remains on his record, but he does not have to serve a day in prison. One reason to use a commutation instead of a pardon is to preserve the illusion of Stone’s innocence.

A pardon typically requires an expression of guilt and remorse, and conveys forgiveness and mercy. With a commutation, Stone may persist in his claims of innocence by challenging his conviction in a motion for new trial and on appeal. Commutation perpetuates the “witch hunt” narrative of Trump’s revisionist history. 

A second, and more important, reason for commutation, though, is that it preserves Stone’s Fifth Amendment right against self-incrimination. This factor makes commutation a much more attractive alternative for Trump...