I'm receiving downvotes pretty much every day, sometimes more than once per day on a wide range of answers without any correlation about the topic and the details of my argument. Perhaps others here have experienced this too. I'm not sure why someone would do this. I'm thinking that it could be Trump as he's likely to be bored due to not being allowed to post on Twitter and Facebook...
It indeed appears that you are the victim of rather unusual downvoting activity. It appears that over the past month, someone downvoted exactly one post of yours per day. Among those downvoted posts are posts made years ago. This pattern indeed looks like a revenge downvoting campaign, stretched out to one vote per day in an attempt to avoid triggering any of the automatic saveguards against voting fraud.
As this is a public forum, I am not at liberty to say much more about who is the most likely culprit, how exactly we know that and what actions we are going to take in this matter. But I think it doesn't hurt if I say that none of the prime suspects appear to use IP addresses from Palm Beach, Florida.
I think this ought to be automatically caught, so I opened a request: Improve the detection of targetted downvoting (failed to catch someone downvoting a user almost daily for a month).