The defendant's misdemeanor conviction was under a Tennessee law which required "physical harm" to the victim, which was why even Scalia (who reads the federal statute more narrowly than the majority) was OK with saying he can't possess a gun. What surprised me was the Alito-Thomas concurrence, which says even a slap would be enough. But they tend to read statutes literally.
It's apparently too much trouble for them to read the Constitution literally.
Anyone who thinks the supreme court is going to protect our rights simply hasn't been paying attention.