What was that leftists like to say about Nazis in a bar? If you tolerate Nazis in your bar, you're a Nazi bar?

Surely that applies here. So many socialists tolerate or even defend terrible regimes, such as that in Venezuela, China, and Cuba. That certainly doesn't mean all socialists tolerate it, but given the track record of socialism in producing authoritarian regimes, I have to think that many (most?) willfully ignore it, which is almost as bad. That doesn't mean every implementation of socialism is bad, it just means I cannot give blanket support to "socialism" and need a lot more qualifiers first.