I don’t like to think of them as insane or unhinged. Was Stalin insane? Probably, but it doesn’t matter. They’re just like dangerous wild animals to me now and they’re running amok.
I agree with everything you said - with some qualifications. Yes, Stalin was a Paranoid narcissist; he feared anyone who might challenge him - in his own imagination. That turned him into a mass murderer. Marxism made it easy since under Marxism the people are property of the state and can be used in the same way as any commodity if it benefits the state. I have heard from people like Bill Ayers over the past number of decades that, in order to convert the United States into a Marxist state, it would probably be necessary to kill at least 20 million people! Seriously!
If you wish to call the present Dems and their rabid followers nihilists instead of insane we can try that: they believe in nothing (except themselves, of course.) But we all can see that the opposition to Trump is not based in reality; instead of ruining everything he was rebuilding everything - and his success was obvious for anyone to see. People who will not accept reality are of questionable sanity - and dangerous!
IMO it is less mental and more spiritual! It is the spirit of this age and must be resisted by honest intelligent people, as gently as possible. But when they are burning your cities to the ground and killing productive citizens, I think appropriate force in indicated.