Do you have any evidence his opinion has changed? If you don't, then it's not misinformation, and no you don't get to demand people "let it go" because it was 16 years ago.
And donating to a specific cause shows a lot more commitment and understanding than a typical vote.
Trying to cancel people based on their political opinions is a lot worse than even the most extreme things you could donate towards. Grow up and learn to live with people different from you.