In all the states that still have the death penalty, a majority of the elected representatives favors the death penalty (or at least they don't want to risk displeasing the voters by trying to get it abolished). Otherwise, the death penalty would no longer exist. And the same is true at the federal level, since there's still a federal death penalty[1].
Those people who are "OK with a few false positives" include legislators, the president, governors, district attorneys, prosecutors, police, etc. In some cases, DAs and other law enforcement officials have fought tooth and nail to prevent old cases from being reopened, since they feared being embarrassed by the truth more than they feared an innocent person being in prison or getting executed. (I think that if anyone deserves the death penalty, it's those who knowingly send innocent people to be executed to further their own careers. That should be considered murder.)
Why shouldn't every case that was based on hair evidence (not just the 2000 that had technical legal errors) deserve to get a DNA test? If they still have the hair sample, they can test the hair's DNA against that of the prisoner. I'd suspect the reason they don't do this is that the government fears that exposing how fallible the legal system is will lead to massive public unrest.
And then there's the whole corrupt plea-bargaining system that induces people to plead guilty to crimes they didn't commit because they're afraid of being hit with the death penalty if they go to trial and lose (which is a high probability for poor people represented by public defenders).
All of these things are possible because of laws which our elected representatives have enacted and enforce.
There are (at least) 51 governments in the USA. For the nth time, it's not a monolithic entity. After all, we have a good numbers of states that have banned or imposed moratoria on the death penalty too, and those states obviously have no compelling interest in preventing scrutiny of its reliability.
massive public unrest
No chance. People (collectively speaking) are indifferent to perfectly well-documented failures of the legal system as it is.
Those people who are "OK with a few false positives" include legislators, the president, governors, district attorneys, prosecutors, police, etc. In some cases, DAs and other law enforcement officials have fought tooth and nail to prevent old cases from being reopened, since they feared being embarrassed by the truth more than they feared an innocent person being in prison or getting executed. (I think that if anyone deserves the death penalty, it's those who knowingly send innocent people to be executed to further their own careers. That should be considered murder.)
Why shouldn't every case that was based on hair evidence (not just the 2000 that had technical legal errors) deserve to get a DNA test? If they still have the hair sample, they can test the hair's DNA against that of the prisoner. I'd suspect the reason they don't do this is that the government fears that exposing how fallible the legal system is will lead to massive public unrest.
And then there's the whole corrupt plea-bargaining system that induces people to plead guilty to crimes they didn't commit because they're afraid of being hit with the death penalty if they go to trial and lose (which is a high probability for poor people represented by public defenders).
All of these things are possible because of laws which our elected representatives have enacted and enforce.
[1] http://www.deathpenaltyinfo.org/federal-laws-providing-death...