Though I don’t always agree with him, I generally find Matt Lewis to be a thoughtful conservative commentator. His response to this week’s botched Oklahoma execution, “The conservative case for capital punishment,” is a good example. That is, it’s a thoughtful piece of writing. And I don’t agree with it.

But first, a few points where I think Lewis is correct. First, whatever your position on the death penalty — and I’m an abolitionist — these botched executions aren’t a particularly compelling an argument against capital punishment. As Liliana Segura has written here at The Watch, the background to the current debate over what drug cocktail states use for lethal injection is complicated and convoluted. We could quite easily execute people with methods that are quicker, painless and more humane. There are many reasons we don’t. One is that the current drug cocktail has already been approved by the U.S. Supreme Court. Switching to something else would subject a state to years of court challenges and litigation (although that is what’s happening now, and it will almost certainly intensify after this week).

Another reason is appearances. If your goal is to carry out a humane execution from the perspective of the condemned, the guillotine and the firing squad are far better than lethal injection. Because of the paralytic agent used in the lethal injection cocktail, we don’t really know whether the people executed this way feel pain. And this obviously isn’t something that can easily be tested. But the humanity component has never been about the humanity of the condemned. What we actually mean by humanity is that we want executions to be humane from our perspective. We don’t want to feel icky about it all. A guillotine or firing squad conjures up uncomfortable images. Lethal injection, on the other hand, is a medical procedure. So long as the paralytic agent works, there’s no twitching or convulsing and there’s no blood. There’s little evidence anyone has died. It’s the method of execution that least resembles an execution.

It’s also worth mentioning that, as Segura pointed out, one reason states are turning to secret drugs obtained from secret and black-market sources is that anti-death penalty activists have been successful at persuading the manufacturers of the previously used drugs to refuse to sell them for use in executions.

Lewis is also correct when he points out that the declining percentage of Americans who support the death penalty (though it’s still a majority) may in part be a luxury that’s come with our dramatic 20-year drop in violent crime. We should reform the police and courts for high-minded principles like equality under the law, civil liberties and fair justice, but there’s no question that it’s much easier to rally support for reform when the country is less fearful of crime. (It also makes it much easier to bring politicians on board.)

Finally, while I don’t agree with him, I do think Lewis’ argument for retributive justice — that the most heinous of killers deserve nothing short of death — is the strongest argument in favor of the death penalty. There’s very little evidence that capital punishment deters violent crime. The number of convicted murderers who escape prisons is also minuscule. But the argument that the people who commit particularly horrendous crimes have simply given up their right to live is a compelling one, particularly when allowing them to live means they do so at taxpayer expense. Death penalty proponent Robert Blecker often makes this argument. (Blecker is also consistent. He argues that the death penalty should be painful, and it should look painful.) It’s a moral argument, and the only real response is another moral argument. Conflicting moral arguments can’t be resolved with logic or data or other empirical evidence.

But here is where I think Lewis’ piece goes wrong:

Other small-government conservatives and libertarians argue that it is inconsistent for people who already distrust big government to grant it the power of life and death over its citizens. As a conservative who believes in ordered liberty, and that it is a responsibility of government to protect its citizens, this argument doesn’t dissuade me — especially now that DNA testing can and should be used to exonerate the wrongly accused.

This is the most glaring contradiction in conservative support for the death penalty, and Lewis really short-shrifts it. I agree with Lewis that protecting us from criminals is a legitimate function — and, indeed, is a primary responsibility of — government. But that crime-fighting is a legitimate state function doesn’t mean that it isn’t susceptible to the same problems Lewis points out when criticizing the things governments do that he believes aren’t legitimate. When it comes to the trappings of public choice and political economy, the corruption of power and tunnel-visioned public officials, the criminal justice system is no different than, say, the Environmental Protection Agency, the Department of Education or the Occupational Safety and Health Administration. Actually, there is one important difference: The consequences of government error in the criminal justice system are far more profound.

Lewis is correct about DNA testing: When it’s dispositive of guilt, it can now be used to both exonerate the wrongly accused and to exclude suspects who otherwise would have been wrongly accused a generation ago. But DNA is only dispositive of guilt in a small percentage of criminal cases. It can be determinative in cases in which it’s clear that the killer also raped his victim. It can also be important in cases where there was a clear physical struggle between the victim and the assailant. But DNA isn’t a factor in most other homicide cases. And even when it’s relevant, it rarely makes or breaks a case. Killers don’t always leave behind DNA. A stray hair found at the crime scene that doesn’t belong to the victim could have come from the real killer. Or it could just be a stray hair that wound up at the crime scene for innocuous reasons. And in cases in which the question isn’t who committed the homicide, but if a homicide was committed (that is, whether a death was accidental or intentional), DNA will rarely be relevant.

DNA testing has shown us that within that small percentage of cases for which it does definitively establish guilt or innocence, there’s an alarmingly high rate of error. DNA testing has shown, for example, that methods of forensic analysis and types of evidence that we once thought foolproof or relatively certain are far from either. DNA testing has exonerated people who were convicted because of bite-mark matching, hair and fiber matching, blood-type matching, testimony from jailhouse informants, eyewitness testimony and even fingerprint matching. (This list isn’t comprehensive, of course.) Here’s the thing: If the state’s misuse of this sort of evidence is capable of convicting innocent people in the small percentage of criminal cases for which DNA testing is dispositive of guilt, it’s almost certainly causing wrongful convictions in all of those other cases for which DNA testing is less important or irrelevant. In other words, DNA testing isn’t a panacea. It’s a wake-up call.

Lewis makes clear that he only supports the death penalty for the most heinous of crimes, and only for those crimes for which the defendant’s guilt is certain. At first blush, it’s hard to quarrel with that position. The rub is that we’ll always need to draw that  line somewhere. How heinous must the crime be? And how certain of guilt must we be? There have been more than a few exonorations in cases in which it seemed unimaginable that the accused people could possibly have been innocent. And yet they were. We now know that prosecutors and police are capable of fabricating and planting evidence. Not that it’s necessarily common, but it happens. That means that even DNA cases aren’t necessarily iron-clad. The science behind the testing may be certain, but the gathering and testing of evidence will always be done by humans and be subject to all the biases, imperfections and temptations to corruption that come with them. Or to put it in terms with which conservatives might better relate: Police, prosecutors and crime lab technicians just as capable as conniving, malevolence and corruption as any other human being. There’s nothing transformative about a government paycheck that ensures altruism, honesty or goodness; the same goes with giving someone a badge or asking him or her to swear an oath.

This was the point of my poll question here earlier this week. If you support the death penalty, you have to recognize that it will be administered by human beings, who are flawed, and then you have to acknowledge the possibility that no system of justice can be perfect. This means that at over time, the probability of executing an innocent person eventually reaches 1. The question, then, isn’t whether you believe an innocent person has ever been executed. The question is how many innocent people you’re comfortable executing.

Finally, Lewis doesn’t explicitly make this argument, but I’ve seen versions of it made by others on the right: There will always be errors. So there will always be injustice. We don’t scrap the whole idea of punishment because some innocents may be wrongly convicted. So why do away with a specific form of punishment?

The answer is that death is irreversible. It’s an obvious answer, but it’s an important one. With a life sentence, there’s always the chance to catch the mistake and ameliorate it. (It can never be fully corrected, of course.) Death penalty supporters make the argument that for an innocent person, life in prison is a punishment that’s worse than death. There’s a pretty easy way to test that theory. Find the exonorees who served decades in prison before they were cleared and released. Now ask them if they’d rather have been executed. I’ve asked a few this question. The response was some version of Are you nuts? I’d be surprised if you could find a single exonoree who would answer yes. I’d be astonished if you could find more than a couple.

One more point. I have no doubt that Lewis in sincere when he says his support for capital punishment is contingent on cleaning up the criminal justice system, fixing the mistakes we’ve discovered and ensuring that only the most vicious killers are executed, and in only the cases where guilt is an absolute certainty. If Lewis is up for prodding his ideological fellow travelers to support policies such as requiring a heightened burden of proof in capital cases, or restricting death penalty cases to a very narrow class of exceptionally horrific crimes (as a task force in Ohio recently recommended after a series of exonorations), that at least would be a good start.

The problem is that the politicians he and other conservatives support — the (mostly) Republican officials and legislators in states like Tennessee, MissouriCalifornia, Florida and Arizona, among others — are expanding the number of crimes for which prosecutors can seek the death penalty and looking to speed up the rate at which they execute people. (In Ohio, prosecutors and conservative politicians have rejected the task force’s recommendations.) They’re doing this even as we’re still discovering wrongful convictions in those states and before they’ve bothered to pass meaningful reforms to address the problems that led to those convictions. In fact, in many cases, they’re rejecting reform at the same time that they’re trying to churn out more executions. Even low-cost, common-sense reforms such as recording police interrogations or ensuring double-blind eyewitness lineups are tough to get by Republican politicians. (Democrats aren’t much better, but that’s a separate discussion.) In other words, Lewis’s position is defensible in the abstract. But that isn’t the way things are playing out on the ground.

People who subscribe to different belief systems sometimes have irreconcilable views on public policy issues with a strong moral component. The death penalty is one of those issues. But conservatives are supposed to be skeptical of government. That is a fundamental part of their belief system. And, except perhaps war, there’s no issue for which the consequences of government error or abuse of power are more absolute, irreversible and profound. Even if they support the idea of capital punishment in principle, it ought to be one of the last issues for which conservatives would be willing to abandon that skepticism. Yet it seems to be one of the issues for which their skepticism is most negotiable.