Those who oppose the death penalty likely were discouraged by a closely watched hearing before the U.S. Supreme Court this past Monday.

Two inmates from Kentucky have challenged the present system of lethal injection, saying the three-drug protocol carries an unacceptable risk of causing excruciating pain in violation of the Constitution's prohibition of cruel and unusual punishment. A different system, perhaps a single dose of barbiturate, would work better, some say.

Leaving aside for the moment the argument that capital punishment is cruel and unusual punishment and an anachronism unfit for our nation today — which it is — does the court have reason to reject the lethal injection standard and insist on a more humane one?

Yes, it does. Any nation that invokes the death penalty in the name of justice has a basic moral obligation to ensure that its executions do not impose needless suffering.

There is some evidence that improper administration of the three-drug poison "cocktail" can cause extreme pain while hiding the effects from those viewing the execution.

But in Monday's hearing, some justices were not persuaded. One cited a study that suggested the single-drug protocol has its own problems, which could lead to challenges on similar grounds. And sending the case back to lower courts for further review could mean, Justice Antonin Scalia warned, a long-term cessation of executions while the issue plays out.

Since September, when the court agreed to hear the case, there has been a de facto moratorium on executions, pending a ruling. That makes sense. At least until such time as the United States joins other democracies and bans executions altogether.