I don’t believe that botnet activity has been limited to one side, based on how reddit has looked this last week.
Example of suspicious postings:
https://www.reddit.com/r/Frisson/comments/7engpr/image_reddi...
Example of suspicious postings:
https://www.reddit.com/r/Frisson/comments/7engpr/image_reddi...
That is a post in frisson where someone is posting a pic that supposedly will generate frisson. There is clearly a campaign to post subreddit themed references to the topic.
The vote counts seem aberrant to me as well.
When the right does it (with parsimony), it's the embodiment of Evil. When the left does it (on an industrial scale), it's virtuous.