He spent the weekend boosting the theory about rigged voting machines, and Monday morning screaming that he won the election he lost.
Here's why that's dangerous.
YouTube is barely moderating misinformation, and right-wing channels are circumventing limitations.
Researchers want players to utterly wreck the idyllic town of Harmony Square so they can understand how misinformation works and how to spot it.
Social media networks have a big blind spot: disinformation in Spanish.
Other popular trends include lies about "the left" orchestrating a coup, and voter fraud.
Facebook did add a warning label on Trump's false claim that the election was being stolen, but did not restrict its spread.
Right-wing media turned a mixup at a polling station in Philadelphia into a daylong "steal the election" meme fueled by Don Jr., Steve Bannon, and Diamond and Silk.
5-Minute Crafts, which has 70 million YouTube subscribers, has been the subject of many theories about its true motives. It's actually just very good at making viral videos.
The night before polls opened, Trump used Twitter to undermine the election, again, and Twitter's response was way too slow.
The campaign ads targeting voters in swing states have already racked up tens of thousands of impressions.
Helping others vote can combat your panicky feelings and minimize the number of ballots that slip through the cracks.