A purer form of democracy is in fact what many more contemporary American (or Western) socialists such as social libertarians have advocated. Again, I can't think of any instances where Zinn proposes a "solution" other then enlightenment (eg' understand that we, the readers and writers of books have mostly been the jailers'[1]) so I wouldn't charecterise him as part of any of those movements. I think that you would classify his work as a part of the Marxist family of intellectual endeavour for other reasons.
Since the most obvious effects of Communist thought were the political-economic systems inspired by it, we tend to think of Communism as being purely focused on these. But, an approach to historical analysis is as much a part of Marxist thought as economic analysis.
Often times, in discussions such as these, people will associate Marxist-type critiques with an immediate conjunction to Communism (almost in knee-jerk fashion), because of the historical reasons you mention.
I think that's unfortunate because as a critical model, there are valuable insights to be gained from Marxist thought, even if you reject (as I do) the idea of Communism.
Sure. Hopefully we will be able to see it in historical context by the 200 year anniversary of The Manifesto. As a model for describing history, its not hard to see the attraction to Marx. He was, after all, a very smart guy.
A contradiction between which of those two word pairs ;)
Seriously though, if you think of Socialism as a group of ideas across different fields, you find a lot of diversity once you get to the applied level. You can get anarchy (the aforementioned social libertarians and others tend towards anarchism) or totalitarianism. Direct democracy or dictatorship.
Say you accept Marx's characterization of history as a struggle between classes, you are moved to rage by The Communist Manifesto,^ it describes the brutal no-nonsense history of civilization in a way that makes sense. There are lots of directions you can go from there. Obviously marx had some pretty specific applications which I read as leading to something not that far from bolshevism, but you don't have to agree with everything.
^I suggest that you read it. For most people, I suspect you'll quibble with bits and pieces that have since (it's been 150 years, after all) been subject to more trial and scrutiny. As a narrative, it is not without predictive power.
Since the most obvious effects of Communist thought were the political-economic systems inspired by it, we tend to think of Communism as being purely focused on these. But, an approach to historical analysis is as much a part of Marxist thought as economic analysis.
Howard Zinn was a historian.
[1] Quoted roughly & ineloquently from memory.