> When intellectuals talk about the death penalty, they talk about things like whether it's permissible for the state to take someone's life, whether the death penalty acts as a deterrent, and whether more death sentences are given to some groups than others. But in practice the debate about the death penalty is not about whether it's ok to kill murderers. It's about whether it's ok to kill innocent people, because at least 4% of people on death row are innocent.

It’s not obvious whether Graham has read a reasonable cross-section of the literature on the death penalty and come to this conclusion (in which case some references might be in order) or whether he's just pulling this out of his arse. I’m not familiar with the literature, but a Google Scholar search brings up the following:

> Although death penalty discourse has always been, and remains, multifaceted - encompassing morality, religion, cost, deterrence, theories of punishment, fairness, race, class, and human rights - we suggest that over the past decade innocence has emerged as perhaps the dominant issue in death penalty discourse with "an unprecedented effect on the debate about capital punishment" (Bandes 2008, 5; Baumgartner, De Boef, and Boydstun 2008, 157). This phenomenon has been referred to by such labels as the "age of innocence" (Rosen 2006, 237) or even an "innocence revolution" (Marshall 2004, 573; Steiker and Steiker 2005, 613). The abolitionist movement has embraced innocence as a new rhetorical asset in the death penalty debate, one with the potential to decisively shift the weight of public opinion in abolition's favor (Radelet and Borg 2000; Bedau 2004a; Acker 2009). "Unlike other challenges to the fairness of capital proceedings, which have failed to stimulate widespread public outrage," Marshall (2004) argues, "evidence of the system's propensity to factual error has the power to open closed minds and trigger reexamination of the costs and benefits of capital punishment" (579). Banner (2002) notes, "the prospect of killing an innocent person seemed to be the one thing that could cause people to rethink their support for capital punishment" (304). He goes on to suggest that "if any development had the potential to change" the popularity of the death penalty, "this was the one" (305). Thus, one scholar claims, "it is no exaggeration to say that wrongful convictions spurred . . . the most successful death penalty reform movement in our lifetime" (Bandes 2008, 4). Already, scholars claim that innocence "has produced a massive shift in the terms of the national death-penalty debate" (Hoffman 2005, 562), a shift "away from moral and procedural considerations, and toward the more substantive question of guilt and innocence" (Hall 2005, 373).

(J.D. Aronson and S.A. Cole, "Science and the Death Penalty: DNA, Innocence, and the Debate over Capital Punishment in the United States", Law & Social Inquiry 34.3 (2009), pp. 603-33, http://www.jstor.org/stable/40539373.)

Perhaps it’s somehow satisfying to Graham to make a wide sweep at ‘intellectuals’ whilst presenting a purportedly distinct argument without trying to determine whether it’s been anticipated, but it strikes me as rather dishonest.