The president asked Attorney General Jeff Sessions whether it would be possible for the government to drop the criminal case against Arpaio, but was advised that would be inappropriate, according to three people with knowledge of the conversation.

After talking with Sessions, Trump decided to let the case go to trial, and if Arpaio was convicted, he could grant clemency.

So the president waited, all the while planning to issue a pardon if Arpaio was found in contempt of court for defying a federal judge’s order to stop detaining people merely because he suspected them of being undocumented immigrants. Trump was, in the words of one associate, “gung-ho about it.”