Americans are supposed to be protected from "cruel and unusual punishments" handed out by their government.
For that reason alone, America should abolish the death penalty.
Last month's order by the governor of California to ban any more executions in the state – one with more people on death row than any other – highlighted again America's bizarre and arbitrary approach to state-sponsored killing.
And showed why that Eighth Amendment to the US Constitution, about "cruel and unusual punishment", is being violated daily.
In California, 737 people sit on death row. The state hasn't executed anyone since 2006 and, even before the governor's ban, showed no sign of firing up the death chamber again.
They sit, technically sentenced to die, but in a limbo.
If a citizen dangled the notional threat of killing someone over their head, we would call that cruel. Why is it any different when the state does it?
This month, the US Supreme Court decided that a man due to be executed in Missouri had no right to a "painless death".
A medical condition meant the lethal injection process would have caused him excruciating pain. His request for nitrogen gas to be used instead was refused.
Justice Neil Gorsuch, appointed to the court by Donald Trump, wrote that the Eighth Amendment allowed execution involving pain just not those "super-adding terror, pain or disgrace".
How is choosing the method guaranteed to cause pain, rather than the alternative, not 'cruel'?
Executions are generally on the decline – there were 25 across the country last year, compared to the peak of 98 in 1999.
Fewer states are carrying out death sentences too – those 98 executions in 1999 took place in 20 states. In 2016, just five states put people to death. This year, just Texas and Alabama have.
If just a few people, in a handful of states run the risk of execution, does that not make it 'unusual'?
Many will question why we should care what happens to a convicted killer who showed little mercy for their own victims, and it is impossible to argue against the desire for retribution.
Public opinion is split and, as that Missouri ruling showed, the US Supreme Court seems unlikely to abolish the death penalty if the question arose.
But death rows cost more than regular incarceration, prolong appeals agony for victims' families and do not deter crime.
States are losing their appetite to execute. The American people will have to make the ultimate decision to end the barbarism – especially when the Constitution they claim to so revere says they should.
* Greg Milam is the US correspondent of Sky News.