I remember it being said of some people years back that "he looks like a Communist". It was usually conveyed by an intense earnestness but sometimes dress and appearance. People had a kind of red-ar then.
Of course it was far from perfect. But even the Communists themselves knew it. They had sessions on how to look "normal".
But it was hard because ideology is not just about abstract belief but being part of tribe. That was the secret of its cohesion and the source of its greatest danger.
