And you think it's about protecting 501c3 status (which probably didn't exist 40+ years ago) and couldn't possibly be a result of an exercise of propriety?
Dear the invisible hand,
If I recall correctly, it was in the 1950s that the IRS adopted rules forbidding explicit partisan political activity by churches.
sitetest
Actually, if someone is widely known to engage in a type of behavior and one is trying to make it clear that the person's behavior is bad, it's often best to condemn the behavior without mention who's doing it. Doing that makes clear that the condemnation is against the behavior, rather than the person. Further, it makes it much harder for the person engaging in the behavior to weasel out of the accusation.
I am reminded of an ad that spoke of IIRC "greedy [anti-gun] mayors filing frivolous lawsuits", without mentioning any names. Funny how even though the ad didn't accuse anyone in particular, some mayors thought it was unfairly targeting them.