When a question is protected it requires a certain minimum reputation to answer it. At least on politics SE this is mostly used for questions that are highly politized or opioniated. And it works in preventing spam, low quality or opinion only answers which such questions are especially likely to attract.
But protecting doesn't do anything about editing the question or answers to it. This means any user with at least medium reputation (2k afaik) can edit the question and any user can suggest an edit and it requires 2 users with at least medium reputation to approve it. In general this works fine but for question that are protected this may not be enough to prevent editorial vandalizing. Again this is a risk for any question but highly politized or opionated questions are especially likely to attrack such attempts.
I would therefore suggest that protected questions also get much higher reputation requirements for editing or approving a suggested edit, possibly all the way to moderators only. After all, if the question is protected that means a moderator already looked at it and thought it is good as is. Otherwise they could have edited themselves (or closed it or whatever else could be appropriate).
While I hope my argument stands on its own, here is the question that inspired my to write it. In my opinion the edit suggested by the low reputation user would count as vandalizing, it removes context with external sources and totally changes the intent of the original question. But then of course I have personal opinions on the topic as well. I could just edit the deleted content back in but starting an edit war seems like the wrong way to go hence a question here.