Only speculations, nothing concrete. My first suspicion when I saw it was that he was hacked — but that’s been ruled out.
Grassley is one of the few in the Senate who’ve known the score from day one, and he’s had other strings of seemingly jibberish texts in the past (usually involving corn and harvesting corn). These seem to be comms of some kind, either for his own team or to the enemy. There are some people who think he’s referencing RGB in the above text thread, to what end I couldn’t tell you.
There have been odd comms on Twitter in the past between players in this game, namely about losing their dogs (Comey did this, as did the Bushes) — right before the death of a major figure was announced (McCain in the case of the missing dog). The theory (take it how you will) is that these people were talking about McCain not a dog, and they knew he was dead before the masses (in this case, the theory goes he was executed). I don’t know where I fall in terms of buying into those theories, but they’re compelling in spots.
(Pre game, pre coffee ramble)