I want to know the answer to the following question:
What do death penalty opponents argue that capital punishment isn't effective at doing?
All the background I'm provided with is that "Opponents argue that the death penalty is not an effective means of deterring crime, risks the execution of the innocent, is unnecessarily barbaric in nature, cheapens human life, and puts a government on the same base moral level as those criminals involved in murder.". Is that enough to answer the question?