From a UK perspective the US acceptance of the death penalty seems amazing. After all it is a defining characteristic of regimes like Iran and China, and the USA does itself no favours inviting comparisons with such regimes.

In Britain we certainly have our "nothing is too bad for these people" lobby who would advocate using the death penalty for terrorists, paedophiles, mass murderers, traitors, rapists, anti-social elements, communists, homosexuals, anyone else they don't like. But thankfully more moderate views have prevailed. "Thou shalt not kill" is a fundamental right enshrined in our ethical code and our laws, and people don't lose this right for any reason. That the state must not kill people through a judicial process open to mistakes and abuse is pretty generally accepted in Britain. And the UK could not deport someone to a country including the USA if we believed they would be executed. Were our government to try to do this the appropriate British national court would intervene, and if necessary it would go to the European Court.

Presumably in time the international community will put pressure on the USA to uphold fundamental human rights and abolish the death peanalty. If the USA did not have the economic clout it does it would have happened long ago. But sooner or later it will happen.