Just write him back and say he obviously doesn't represent you as he is completely uneducated about the issues you find important. Tell him you are going to start a campaign to make sure that all of his constituents know his position and start a petition to demand his removal from office or ensure he does not get re-elected. That should get his attention. You're basically saying hey buddy in case you didn't know you work for us and we can get you fired and make sure you never work in this town again. Unfortunately it will take much more work than just writing an angry letter, stay strong and educate those who blindly follow authority to think for themselves. I wish you the best of luck in your efforts. My thoughts and energy are with you.

Blessed be~