We really don’t need to know who the writer is, if one actually exists, because he has given us all the information one could need to asses his credibility. When you read someone praising McCain, and speaking of him as a model for politicians to follow, you know without a shadow of a doubt the author is either a liar or a moron living in a fantasy world.
Thankfully, senator McCain is still dead so I propose the “senior official” is Omarosa or some clerk in housekeeping. This will be fun to watch