Okay - you're right. I'm surprised none of those show up in a title search. Reddit's search feature must be broken, because title queries are supposed to show even if the author is deleted.

So it looks like someone did make super obvious sockpuppets that posted some pro-Democrat content once. I still don't think you can generalize that to a trend - certainly nothing on the order of the Russian bots. If anything, /r/politics had a reputation at the time of being extremely favorable to conservatives.