Actually, I think he wants to spend quality time with his wife Donna, his daughter Laura and young granddaughter.
With Royal no longer with us, I think he realized it was time for a long and rejuvenating rest.
Besides that, Monica (Kaufman) Pearson just retired so he has no nemesis at the station.
The whole Cain circus-act candidacy just seemed like a ridiculous run-up to a handoff from Boortz. Preplanned? Tinfoil isn’t just for hats.