Reply #15: Thank him for warning you of that right-wing smear email that is going around

[tandot]

Tell him that you already know about it and say something like "Isn't that absolute appalling that those right-wingers stoop so low and make up stuff like that about an honorable man"

Maybe you could include all the links debunking the story and say "You've probably already seen most of those stories debunking these lies. I am sending you the links just in case you need to send it to the person who sent you that god-awful right-wing email"

Maybe this is the most tactful way to give your grandpa the facts without making him feel bad.

edit for spelling