Stick the reply on pastebin with a note explaining how it doesn't stop pedophiles and terrorists, explain how it protects incumbent pedophiles in the political class as per pizzagate, then post it on reddit, 4chan and to the opposition (actually forget the latter as they're just as bad).
I do wonder (perhaps naively) whether this is a genuine misunderstanding of the argument for privacy/encryption or something more malicious. Is it that politicians haven't spent enough time thinking about this or are they willfully ignorant of the wrongness of their argument?
That distinction doesn't really matter. Willful ignorance by anyone in power should definitely be classified as malice. Remember that as your representative, they should be able to explain their actions to you.
It's an interesting point. If they are ignorant (perhaps without the wilful), then perhaps when you present them with facts and information, they might change their mind. If they are malicious, they won't change their mind in the face of any facts or information, because their motivations are underhand and cannot be reasoned with.
I suspect in cases like this it's probably a bit of both (and perhaps in the case of this particular MP, she might just be toeing the party line).
Time is up for this attitude.