By its fruit, the tree is known.

Great discussion of Communism vs. Nazism at Instapundit.
One excerpt:

I'll repeat: The difference between Communists and Nazis is mostly PR, and the PR is better because more journalists and academics were communists than Nazis.

And reader Michael Ravine notes what Robert Heinlein said about communism: "I regard it as Red fascism, distinguishable from black and brown fascism by differences of no importance to me nor to its victims."

Some Communist apologists appear and are rebuked.