SCOTUS has ruled that the death penalty _is_ cruel and unusual punishment in many circumstances.

For example, in 1980 they ruled that it could only be applied only if it involves a precise and aggravating factor[0].

Louisiana had a law that made the rape of a child punishable by death and SCOTUS overturned that law in 2008[1].

SCOTUS has consistent narrowed the crimes punishable by death in the past 50 years using the Eighth Amendment as a justification.

[0] https://en.wikipedia.org/wiki/Capital_punishment_in_the_Unit...

[1] https://en.wikipedia.org/wiki/Kennedy_v._Louisiana

Just look at the number of executions of people with mental handicaps and tell me the current justice system is capable of acting in a just fashion. https://deathpenaltyinfo.org/list-defendants-mental-retardat...

The parent has not made such a claim.

s/"in many"/"in certain, very specific"

That does not change the fact that SCOTUS has upheld the death penalty generally as being a Constitutional punishment.

Your substitution is inaccurate. The rulings effectively mean that the death penalty is cruel and unusual except in certain, very specific circumstances. Only the most extreme crimes qualify. Even the rape of a child is not extreme enough unless done multiple times. It might seem applicable to only a few cases, but that is only because few states attempt to apply the death penalty except in the most extreme circumstances.

A lower level court judge can make a ruling, like finding a $250 fine for a poor person cruel, that stands, because it's not a SCOTUS issue. The death penatly sure, and the legality of it has already been decided in the U.S., and is usually for serious crimes. But for low-level offenses, the likes of which are rarely — or basically never — brought before SCOTUS or higher level courts, a judge can rule in any way he sees fair, as that's his job.

> Only SCOTUS can reverse its position on the Constitutionality of the death penalty.

Yes, although there are many things that SCOTUS ruled constitutional that are just unpopular in this day and age that nobody treads in that territory.

So we and all the states have the choice to just not practice that, for example. Yes, in this case that is unlikely. Still an option.

Of course the states are free to outlaw the death penalty, that doesn't address whether or not it is Constitutional. There are plenty of things that are completely Constitutional but which are outlawed in the majority of states.

As far as popularity goes though, the death penalty has been more popular than not for all but a brief time in the 60's[0], and I think it's dangerous to conflate popularity with Constitutionality, or to suggest even implicitly that they should have any bearing on each other.

[0] https://news.gallup.com/poll/1606/death-penalty.aspx

But SCOTUS can only reverse what is brought to it, right ? So a circuit court judge has to ignore that so that SCOTUS can have the occasion to reverse its position ?

Bear with me, I am not from the US.

That's not quite how it works. The lower court would be expected to uphold SCOTUS's rulings, though there is some wiggle room.

The main way things get before SCOTUS is through the parties appealing the lower court decisions and then SCOTUS deciding to hear it.