A U-S Supreme Court ruling barring the death penalty for crimes other than murder could signal a coming end to capital punishment in any context.

Two men were awaiting execution in Louisiana for raping children. The 5-4 ruling taking them off Death Row follows recent rulings prohibiting the execution of the minors and the mentally ill.

"Its application is being narrowed to the point where states will be increasingly wary of implementing it," says Indiana University law professor Jody Madeira. "And when a state is afraid of implementing a punishment, it will eventually disappear."

Madeira acknowledges the court recently reaffirmed the constitutionality of the death penalty itself, in a ruling upholding lethal injection as an execution method. But with as many as three justices believed to be close to retirement, Madeira says the election of a Democratic president could hasten the end of capital punishment.

Five states besides Louisiana have laws on the books allowing capital punishment for crimes other than murder, but the laws in Florida, Montana, South Carolina and Oklahoma have not been enforced in decades. Texas passed a law allowing the death penalty for the rape of a child last year, but has yet to use it.