A terse statement like this will do:
Having listened to the program and read the transcript it is evident to us that your letter is based on lies, obfuscation and an unholy attempt to chill the speech rights of a private citizen and an entire broadcasting network.
You may therefore and forthwith kiss my ass.
Regards,
Mark Mays
The letter is here; its a pdf so I can’t cut and paste it here. But you can read it here:
http://www.politico.com/static/PPM43_071002_reidletter.html
Its mediocre, imho.