Your strongly worded letter to people with a similar point of view should do the trick.
Hey, I know, how about instead of writing letters to other true-belivers in the choir, you convince 3, 4 or 5 people in your life to vote with you who might otherwise not - and make sure they get to the polls on election day.
Now THAT would be a message.
I have already been doing that. I didn’t convince 3-4 people either. Try dozens.