You just moved the goal post the wrong way.  Trump misunderstands how it is supposed to work. You wait for sentence, you work with DOJ, you make decision. 

This sums it up well.

The Constitution gives the president nearly unlimited power to grant clemency to people convicted of federal offenses, so Mr. Trump can pardon Mr. Arpaio. But Mr. Arpaio was an elected official who defied a federal court’s order that he stop violating people’s constitutional rights. He was found in contempt of that court. By pardoning him, Mr. Trump would show his contempt for the American court system and its only means of enforcing the law, since he would be sending a message to other officials that they may flout court orders also.