The bitterness is evident with a glance at blog sites. On the liberal side, there are pictures of obscene practices, shrill denunciations of Mr. Cheney, and headlines like, ''Torture is foreplay for war.''

On conservative sites, the analyst Bill Kristol boasts, ''Bring it on.'' There are headlines like ''Declassify Obama's native-birth along with torture memos.''

The agenda for much of the left is vengeance, to thoroughly discredit the Bush administration. For much of the right, including Mr. Cheney, it's to play on fears that America is vulnerable because Mr. Obama isn't tough enough on terrorists.

The issue won't go away.

Torture was used extensively on some captives in 2002 and 2003, with dubious legal justification and debatable results, and the U.S. government lied to its citizens. Critics contend it would be harmful to U.S. intelligence and foreign relations to expose policies and techniques that may prove embarrassing while the United States is in the middle of a war. They forget that the Roberts Commission was established to investigate the Japanese assault on Pearl Harbor 11 days after the surprise attack.

Others suggest that this is a partisan witch hunt. That ignores that many top Republican officials, at the time and since then, vehemently opposed these practices.

The infamous legal justifications for the policy crafted by the Justice Department's Office of Legal Counsel, then headed by Jay Bybee, now a federal judge, and John Yoo, were ridiculed and overturned by subsequent Bush appointees to that office.

Ali Soufan, a Federal Bureau of Investigation expert on Al Qaeda, revealed that he got more information from one of the captured terrorists using conventional methods. He was so appalled when Central Intelligence Agency contractors started using torture that he objected and reported it back to F.B.I. headquarters. The F.B.I.