Honestly, if I was trying to manipulate online discourse to deliberately cause as much political turmoil as possible, not only would I do agitprop for the far left and far right to anger the other side, I would also make sure to post a large amount of centrist propaganda that is callously dismissive of legitimate issues and suggest that foreign manipulation is part of it. That would both piss off at least one side (depending on the issue) and cast doubt on the idea that foreign manipulation is actually even happening in the first place.