How about "TrueLeftist" or "anti-Duginist".
I would settle for "LeftistHawk", if neither you nor 90sRF object. I will include "True Leftist" and "anti-Duginist", as well as of course "anti-Zionist", in the description. As soon as I have your "go ahead", I will register an e-mail address in this name and ultimately create the twitter account.