In one of the more nauseating passages, Jay Bybee, then an assistant attorney general and now a federal judge, wrote admiringly about a contraption for waterboarding that would lurch a prisoner upright if he stopped breathing while water was poured over his face. He praised the Central Intelligence Agency for having doctors ready to perform an emergency tracheotomy if necessary.

These memos are not an honest attempt to set the legal limits on interrogations, which was the authors’ statutory obligation. They were written to provide legal immunity for acts that are clearly illegal, immoral and a violation of this country’s most basic values [...]

At least Mr. Obama is not following Mr. Bush’s example of showy trials for the small fry — like Lynndie England of Abu Ghraib notoriety. But he has an obligation to pursue what is clear evidence of a government policy sanctioning the torture and abuse of prisoners — in violation of international law and the Constitution.

That investigation should start with the lawyers who wrote these sickening memos, including John Yoo, who now teaches law in California; Steven Bradbury, who was job-hunting when we last heard; and Mr. Bybee, who holds the lifetime seat on the federal appeals court that Mr. Bush rewarded him with.

These memos make it clear that Mr. Bybee is unfit for a job that requires legal judgment and a respect for the Constitution. Congress should impeach him. And if the administration will not conduct a thorough investigation of these issues, then Congress has a constitutional duty to hold the executive branch accountable. If that means putting Donald Rumsfeld and Alberto Gonzales on the stand, even Dick Cheney, we are sure Americans can handle it.