The fact that the US federal government has the power to outlaw this but doesn't, that this specific execution was brought before the Supreme Court and they voted against blocking it 6–3, and the fact that the majority of US states (27) and the federal government have this on the books speak for the US now, yes.
Taken to an absurd extreme, let's imagine that the US federal government and 27 of its states explicitly had statutes on the books stating "you can legally rape puppies", and you stepping in and saying "Well that doesn't speak for the entire US! Stop trying to make it sound like everyone condones puppy rape just because Missouri allows it!" Would you say that then? Because I feel like any rational person would be asking "Why does the US allow this to happen?" If not, why would you say it here? The US is simply backwards in this regard.
Would you come to the US' defense in the same way that you are right now over state-sanctioned murder in the situation I outlined? It's a very simple yes/no question that you're tiptoeing around for seemingly no reason.
Damn, last I checked, 27 plus the federal government was more than 1. Maybe the federal government expressed as an integer actually comes out to negative 26 and makes your ridiculous defense make any sense.