Dear [Name], 

I am writing to express my opinion on [issue]. It is my belief that [opinion on the issue]. I think it is important for [reason], and I urge you to [action]. This issue is one of great importance, and I urge you to do the right thing and make a difference. 

Sincerely, 
[Your name]
Componi una lettera a un personaggio politico esprimendo la tua opinione su una determinata questione.