"Dog" and "Capitalist" I get, but "Running?"

How is that insulting? Or is something lost in the translation? “Dog with the runs?”

I think I heard that’s the equivalent of “communist sympathizers”, i.e. those who don’t necessarily benefit but support it anyway, i.e they are lowly yet loyal like a dog running aside its master. But I’m not 100% certain on that.

I seem to remember learning the term as “Capitalist running dog lackeys”. Could it be because they are always scrambling around trying to get ahead?

I always figured it was a “running away like the cowardly curs they are” kind of thing.