Yes, there is an emergency alert system that delivers audio messages from the President.
Yes, his appointees on the FCC reminded providers about compliance a few days ago.
But who cares?
A recorded message is not a game changer. If Trump prattles on with demented stuff like the OP, about good vs evil and cleansing, most people will laugh or switch off.
Trump lost the election. Lost the court cases. Lost the electoral college.
Why would another recorded message from a loser - who never stops whining and we have heard it all before - change anything?
