They know we know,
.
https://cdfca.org/about/leadership-and-staff/board-of-directors-2/
hard to sue a public figure for libel
The law as written is a masterpiece of cult "have it your way" but it is specific:
to be guilty of libeling a public figure, a defendant must show "reckless disregard for indications of probable falsity"
Letter from POTUS is an "indication of probable falsity."
Clearing a wide path for conviction of these entities for libeling a public figure.