Uncomfortably un-theoretical. (AP Photo/David Tulis) (David Tulis)

At a Republican debate, mention that Rick Perry executed more than 200 people in his time as Texas governor caused the audience to explode in, frankly, eerie applause.

As Elizabeth Flock at BlogPost points out, all signs indicate that the death penalty is something we, as a country, favor. And this is recent — 44 years ago, only 40 percent of people supported the death penality for someone found guilty of murder — smaller than the percentage that opposed it.

But now, according to a Gallup poll, support for the death penalty for a person convicted of murder has shot up to 64 percent, while just 20 percent of people oppose it.

Execute the guilty? Sounds like a plan.

But the trouble is that nothing is ever quite so simple. We have the idea that everyone executed is functionally Hitler. That is why we want them executed.

But unmitigated Hitlers are in rather short supply.

And so every few months or so you are faced with a modified version of the classic problem. This month, it is embodied by a man named Troy Davis, convicted of shooting a police officer in Georgia.

"I would rather see ten guilty men go free than one innocent man perish," some say.

"I would rather execute eleven people than just the one," others say.

Except that these people being executed are no longer theoretical, black-and-white. They are actual human shades of gray— avowedly guilty souls like Lawrence Brewer, or men like Troy Davis who have attracted the support of high-profile figures from Desmond Tutu to Jimmy Carter, who say that he failed to receive a fair trial, that the eyewitness testimony used to convict him has come into question.

Roar if you like. But supporting the death penalty means reconciling yourself to the idea that every so often someone will come along and yell that you are executing an innocent man, or that you are executing someone who hasn't gotten a fair trial.

There are strains on both sides of the question. There are people whose crimes are so heinous that even the generally merciful tend to feel that death is the only recourse. And on the other side, there are people whose trials were so botched that putting them to death seems less appropriate than offering an abject apology.

These days, most everyone’s for executing guilty people.

But where do we find these perfectly guilty people, and the perfect process that results in that perfect conviction? In forty years, we have seen Science and Expertise blossom in the courtroom. But is the process fairer now?

There is the stark, easy contrast of theory. But then come slippery facts and non-theoretical juries.

Guilty? Innocent? Can we tell, from our armchairs? Beyond a reasonable doubt?

There is a steadily increasing mound of information that suggests that whether or not someone is convicted depends as much on what the judge has eaten that morning, the unconscious non-verbal cues of the officer showing the line-up, or some equally obscure concatenation of factors as on the facts of the case. Sometimes we can agree that this is justice. Other times, the glove doesn’t fit and we wander off in a haze.

This is no revelation. The justice system was designed with the expectation that human beings were flawed, even at best, and the only way around it was to build a framework with the narrowest margin of error you could and give those on trial the chance to challenge the proceedings when they seemed unfair. And we are not so barbaric as we were. In the earliest days, no one considered DNA, and men were killed for being warlocks. Now we know better. And we are learning all the time.

The statistics from Gallup suggest that a majority of Americans are at peace with the present margin of error.

Perhaps we are. But then there’s Troy Davis. Nine hundred thousand signatures on online petitions. Indignant editorials. Twitter ablaze.

Tonight, there’s a man caught in the margins. Perhaps he’s guilty. Perhaps he’s innocent. But amidst all the tweets and protests and petitions, the indignation and the outpouring of questions, I keep hearing that curious roar.

Most Americans support the death penalty. In theory.