I don’t think your second sentence proves your first. The US has well over 100 million voters, the number of social media users is probably much larger.
Even 1000 separate people accusing you every day would be a tiny drop in that bucket.
My guess is that the vast majority don’t really buy it, but don’t realize that everybody around them also doesn’t. Probably because they don’t really care that much.
My take is that modern political persuasion is still at the level of 1970’s commercial advertising. They’ve been inoculated. Long ago. All their lives.
So all of these people, whoever they vote(d) for, aren’t going to go on social media to shove dumb arguments at people they don’t agree with.
Only a comparative handful of fanatics and people who consider themselves well informed, whether or not they are.