Theres no way to prove beyond a reasonable doubt he was on substances when he purchased the firearm. The form asks if you're a USER of drugs. If he was not using substances when he was buying the firearm, he didn't lie.
That's fine. If this is now precedent, the government needs to go and retroactively charge all users, and not just a spotlight democrat.
For anyone wanting to sit on the sidelines, this is what is going to happen. trump WILL open camps, and these people will refuse to cover it.
Abstain at your own peril.