Of course the leftists on the court are ok with applying 2A to stunguns. Soon they will support a ban on all firearms based on, “well stunguns are still legal so you 2A types are over reacting.”
The Alito concurrence also addressed that:
The lower court’s ill treatment of Heller cannot stand. The reasoning of the Massachusetts court poses a grave threat to the fundamental right of self-defense. The Supreme Judicial Court suggested that Caetano could have simply gotten a firearm to defend herself. ... But the right to bear other weapons is “no answer” to a ban on the possession of protected arms.