is communist propaganda copyright protected?

This site may help you:
http://www.whatiscopyright.org/

Yes it is, the details like how long, who may use it, how, when, where
etc is all dependant on what country you are located in and where it
was created. Where was the peice created that you have an interest in
and when? Where are you located?

I don't think this question can be answered in any meaningful way.
"Communist propaganda" is a very broad category. This is like asking
"is satire copyright protected?" - obviously the answer is "some is,
and some isn't."

Without the specific name of a certain book, magazine, article, or
other literary work, it's not possible to know whether something is
copyrighted or not. And, of course, we'd also need to know which
nation's copyright laws are under consideration.