That might be the intended purpose.. but there are unintended consequences.

I think we need support for something like steem-communities (reddit-style subscribed content) to get people content they find appealing.

Could we have communities like /r/sandersforpresident or /r/thedonald if they are allowed to down-vote each other?

Sure. But their reward pool contribution will be negated, so why would they come here in the first place?