The example I'm thinking of is Gerald Kaufman who clearly had a huge personal disconnect with the zionism he wanted (I'm pretty sure he always claimed he was Zionist at heart) with his extreme rejection and rhetoric against Israel. It's clearly complex, but I think we're on clearer ground talking about what exactly he said rather than speculating on the nature of his thoughts.
With Kaufman there's also the really awkward extra issue that for the last few decades of his life he was clearly slowly succumbing to some sort of dementia (it was an open secret on the Parliamentary estate by the end) but because he had always had a rather sharp tongue alarm bells at some of the more disturbing things he said did not go off until quite late in the day, i.e. by the point at which the situation was painfully clear.
Poll
