Too insane to die?

The New York Times this morning has this front-page article on the death penalty and mentally ill defendants entitled "Judging Whether a Killer Is Sane Enough to Die."  Here's a taste:

Two decades ago, the United States Supreme Court in Ford v. Wainwright ruled that the Eighth Amendment prohibited the execution of the insane.  Since then, lower courts have struggled to find a way to apply that principle in practice....

"In Texas," said Greg Wiercioch, a lawyer with the Texas Defender Service who has consulted with Mr. Panetti's defense, "if you cast a shadow on a sunny day, you're competent to be executed." Other courts require more.  Relying on a concurring opinion in the Supreme Court decision, they say the inmate actually has to perceive the connection between the crime and the punishment.