You should read the whole thing, of course, but here is one of the more noteworthy portions from Justice John Paul Stevens' essay on the death penalty in the current issue of The New York Review of Books:
In 1987, the Court held in McCleskey v. Kemp that it did not violate the Constitution for a state to administer a criminal justice system under which murderers of victims of one race received death sentences much more frequently than murderers of victims of another race. The case involved a study by Iowa law professor David Baldus and his colleagues demonstrating that in Georgia murderers of white victims were eleven times more likely to be sentenced to death than were murderers of black victims. Controlling for race-neutral factors and focusing solely on decisions by prosecutors about whether to seek the death penalty, Justice Blackmun observed in dissent, the effect of race remained “readily identifiable” and “statistically significant” across a sample of 2,484 cases.
On that note, here is a chart from Sociological Images (by way of Amnesty International) that illustrates the extent to which the criminal-justice system is far more likely to deal out death if a white person was the victim:
We have a black president, sure, but when you add up the evidence, it's abundantly clear that as a nation, we don't actually place that high of a value on the lives of our African American citizens.
-- Jamelle Bouie