Attorney General nominee Michael Mukasey told senators Tuesday he will reject White House political meddling and overstepping its authority in terrorism cases if approved to run the Justice Department.

He said he would resign if his legal or ethical doubts about administration policy are ignored.

Mukasey's plans for the scandal-scarred Justice Department starkly contrast with how it operated under the man who would be his immediate predecessor — former Attorney General Alberto Gonzales.

Mukasey, a retired federal judge, said he also would review all of the opinions issued by the department's Office of Legal Counsel to make sure they are legally sound. He described as "defective" a 2002 memo that defended the Bush administration's use of torture techniques against terrorism suspects.

That opinion "was worse than a sin, it was a mistake," Mukasey told the Senate Judiciary Committee. "It purported to justify measures based on broad grants of authority that were unnecessary."

Likewise, on politics, Mukasey said he would discourage his prosecutors from bringing charges against political candidates shortly before elections and would not let party loyalty be a consideration for people applying for Justice Department jobs.

"That's the standard I'm going to make very clear, very precise, and I'm going to enforce," Mukasey said.

It was a far cry from the policies Gonzales allowed before he resigned in September after months of criticism and questions about his honesty.

An internal Justice Department investigation is looking into whether Gonzales lied to lawmakers about the administration's terror programs and illegally let politics influence hiring and firing of prosecutors. Gonzales, a close friend of President Bush and a former Texas Supreme Court justice, has denied any wrongdoing.

The scandal tainted the Justice Department's long-cherished independent image and has demoralized its 110,000 employees.

"This is a job interview for a big job, a big job that has become even bigger," said Senate Judiciary Committee Chairman Patrick Leahy, D-Vt. "The next attorney general has to begin to regain the public trust."

"I'm awaiting an attorney general who will tell the president some things he may not like to hear," added Sen. Arlen Specter of Pennsylvania, the panel's top Republican.

Mukasey will all but certainly be confirmed as the nation's 81st attorney general, and Sen. Charles E. Schumer, D-N.Y., predicted he may win unanimous support from Democrats who control Senate Judiciary Committee — a panel generally suspicious of Bush's nominees.

As Mukasey was testifying on the first of potentially three days of committee hearings, Bush urged the Senate to confirm the attorney general hopeful next week. Senate Democratic aides said that was unlikely.

Mukasey addressed a half-filled hearing room in a daylong appearance that was pre-empted for about two hours by the Dalai Lama's visit to the Capitol. The hearing promised none of the drama that marked the Senate committee's often-combative questioning of Gonzales earlier this year.

But Mukasey did not get off unscathed.

Sen. Russ Feingold, D-Wis., hammered Mukasey for writing a 2004 speech that derided criticism of the USA Patriot Act as "recreational hysteria." He also described as "somewhat troubling" Mukasey's reluctance to say whether he thinks the administration's terrorism surveillance program crossed the legal boundaries of a 1978 law setting limits on government spying in the United States.

Mukasey said he has not seen details of the surveillance program or other classified Bush administration policies and could not provide an educated answer. He responded similarly to other pointed questions about indefinitely detaining terror suspects and current methods to torture some of them.

"Judge Mukasey, you're punting now," Specter chastised during a legally technical discussion about rights given to detainees.

Mukasey said he wanted to be careful talking about a legal argument currently being considered by the Supreme Court.

"I'm going to have to do what I was told to do when I was a kid, which is 'I have to watch my mouth about this,"' Mukasey said.

"Well, you can punt a little more easily when that issue is before the court, I'll grant you that," Specter answered. "But there are many issues which are going to come to you where a court decision is a long time away."