If someone were to take over that account an issue a call to arms for the QAnon crowd, it could be disastrous.

You aren't wrong. If Trump suddenly tweeted that QAnon followers should murder as many leftists as they can and that he'd personally commute their sentences, I think we'd see at least a few people respond by doing what they are told.

I can think of much, much worse. The USA is a tinderbox all it takes is the right match.

There are any number of really bad scenarios. The militias and the QAnon folks scare me the most at the moment.