Don Lemon linked "lodestar" to military and hence Kelly. I have never heard that word before.
I don't know what Don Lemon said, but the word "lodestar" is linked to Michael Pence, not John Kelly. That is, Pence has used it quite often in his speeches. Most of the linguistic clues seem to point to Pence's style, and he stands to gain the most from an Article 25 action or an impeachment/conviction of Trump. Also, the tone of the letter suggests a fairly conventional conservative Republican, which matches Pence's way of thinking. I suspect that this letter was written by Pence and his speech writer, possibly in collusion with Dan Coats, who is an Indiana politician and personal friend of Pence. Coats is known to harbor similar attitudes and could likely be the "high official" who "could be fired" that delivered the letter to the times. Pence himself cannot be fired, but his effectiveness and future plans would be jeopardized, if he were discovered to have written the piece. Coats could take the fall for Pence, if he were found out to have delivered the letter.
Anyway, that's my conspiracy theory, and I'm sticking with it. For now.