If they're trying to pull America apart like a piece of taffy, it makes sense to do it from both ends. Bernie was the furthest left viable candidate last election (sorry Jill Stein). At least that's how I figured it.
Although they also made efforts to support Jill Stein so as to deplete votes from Hillary. You probably saw that, just posting it here for completeness. Man, it's like, I hate the two party system, and I'm not completely opposed to further investigating Hillary, but this election meddling business is on another level of wrongness. I also keep wondering about the extent of American influence operations in Russia, but then I question how much of my concern should be negated by their comparative lack of true democracy. Too many unknowns. I hate unknowns.