I wouldn't say they're that controversial. I know plenty of gun nuts who are fine with them being illegal.
I would say the controversial issue is what constitutes a bump stock? You can have the same effect with a rubber band
What if you stick some sort of servo to the gun that keeps on pulling the trigger? Then you'd have accuracy and high rate of fire. Would that be illegal?
It's obvious, we need to ban fingers /s
I discount his firearm knowledge based on the fact he says "clips"