This isn’t about Trump, it’s about the second amendment. If the watch list was made up of credible terror threats, it might make sense. But the FBI considers people that even talk about the constitution possible terrorists.
You are right. This is about how stupid and incompetent the “watch list” has become. If the “watch list” was administered competently, by good minds, making sure those on the list didn’t have access to weapons would be a no-brainer.
Unfortunately, as it stands now, administering the “watch list” seems to have been handed to people who flunked the Postal Service test.