ARepublican senator is trying to muscle Atty. Gen.-designate Eric H. Holder Jr. into promising not to conduct “witch hunts"-- code language for criminal prosecutions -- of intelligence operatives who engaged in torture during the Bush administration. It’s an outrageous demand, and it would be unethical for Holder to accede to it.

Sen. John Cornyn (R-Texas), who insisted on a delay in a committee vote on Holder’s nomination, wants Holder to say “what his intentions are toward our intelligence personnel who were operating in good faith based on their understanding of what the law was.” Cornyn was reacting to Holder’s entirely appropriate description of waterboarding as torture. Cornyn’s own attitude toward what are euphemistically called “enhanced” interrogation methods was evident when he rhetorically asked Holder if the nominee would oppose waterboarding if it saved “perhaps tens of thousands of lives.”

Cornyn is free to endorse torture and to vote against Holder’s confirmation in the Judiciary Committee (which is expected to vote today) or in the full Senate. But asking that a prospective attorney general commit in advance to prosecute -- or not prosecute -- potential defendants crosses an ethical line. Cornyn, a former state Supreme Court justice, should know that. No less than a nominee for the federal courts, a prospective attorney general shouldn’t put himself in the position of prejudging cases in exchange for Senate confirmation.

Opponents of any criminal investigation of CIA interrogators -- or of Bush administration lawyers who gave them cover -- argue that President Obama himself has hinted that he isn’t eager to launch prosecutions. It’s true that when the president was asked whether he would appoint a special prosecutor to investigate torture and wiretapping under the Bush administration, he said that “we need to look forward as opposed to looking backwards.” But, in the same interview, Obama said: “I don’t believe that anybody is above the law.”

As this page has argued, Obama would be unwise to succumb to political pressure and announce an open-ended criminal investigation of Bush administration anti-terror policies. Such a knee-jerk initiative, as Holder said at his confirmation hearing, would “criminalize policy differences” between the Bush and Obama administrations. Moreover, it would be permissible, as a matter of prosecutorial discretion, for the attorney general to conclude that it would be impossible to convict Bush-era officials who acted as part of a post-9/11 response to terrorism. But those decisions require a review of evidence, which Holder, at this point, does not have.

A conscientious attorney general will weigh many factors in deciding whether to bring criminal charges. Pleasing a senator who voted to confirm him isn’t one of them.