Michael Mukasey offered his response Tuesday to a set of 495 questions posed by the Senate Judiciary Committee, but his amended answer on whether waterboarding is torture may not be enough for Senate Democrats looking to sink the attorney general nominee.

In the response to the Committee's Oct. 23 letter, Mukasey said Tuesday that waterboarding was "repugnant" to him personally, "but hypotheticals are different from real life, and in any legal opinion the actual facts and circumstances are critical."

Mukasay wrote that as a judge, he "put aside strongly held personal beliefs when assessing a legal question because legal questions must be answered based solely on the actual facts, circumstances, and legal standards presented."

That response didn't satisfy several Judiciary Committee Democrats.

"I remain very concerned that Judge Mukasey finds himself unable to state unequivocally that waterboarding is illegal and below the standards and values of the United States," Senate Judiciary Committee Chairman Patrick Leahy, D-Vt., said in a statement.

“I am disappointed by Judge Mukasey’s response," added Sen. Joe Biden, D-Del., a Democratic presidential candidate. "He was asked a direct question on the specifics of waterboarding and he refused to unequivocally state that this practice is torture. For this reason, I shall oppose his nomination to be the United States Attorney General. Waterboarding is by any standard, torture."

Other Democratic presidential candidates who are U.S. senators — Barack Obama, Hillary Clinton and Chris Dodd — have all said they would oppose Mukasey.

But Sen. Lindsay Graham, R-S.C., told FOX News Tuesday that he was satisfied with Mukasey's response. Graham spoke prior to receiving Mukasey's answers, but said he had received verbal assurances from the White House as to what Mukasey intended to say.

Waterboarding — an interrogation technique that simulates drowning and some say is a form of torture — is expressly banned in the U.S. military's field manual as a tool to interrogate detainees. However, the CIA, and other government agencies are not prohibited from the technique.

Biden introduced legislation this summer to make the practice illegal after lawmakers did not include it in legislation passed last year defining other forms of torture. Mukasey's opponents now say it's wrong for the retired federal judge not to condemn the use of waterboarding by civilian interrogators not governed by the military's prohibition.

"I have not been briefed on techniques used in any classified interrogation program conducted by any government agency," Mukasey wrote. "For me, then, there is a real issue as to whether the techniques presented and discussed at the hearing and in your letter are even part of any program of questioning detainees," he wrote.

"In the absence of legislation expressly banning certain interrogation techniques in all circumstances, one must consider whether a particular technique complies with relevant legal standards," he wrote.

Leahy said he would wait for Mukasey to respond to other written questions and letters sent to him last week by senators from both sides of the aisle, and would consult with Sen. Arlen Specter and other Judiciary Committee members before scheduling a vote on the nomination.

Earlier Tuesday, a senior Judiciary Committee member said that Mukasey's vague answers on waterboarding had so eroded support for his nomination that he would fail a key vote unless he provided an improved answer.

"If the vote were held today, he (Mukasey) wouldn't get through the committee," the senior Committee member said. The senator asked not to be named because of the sensitivity of the issue.

The reservations of both Republicans and Democrats on the Judiciary Committee — which first must vote to make its recommendation to the full Senate — has thrown a major roadblock before a nominee who at first seemed like a shoo-in.

Three Democrats on the White House campaign trail now have announced they will not support Mukasey — turning the nomination into a campaign issue.

Top committee Republican Arlen Specter on Tuesday tried to deflect some criticism of Mukasey regarding torture.

Specter said that because the Senate last year voted down naming waterboarding as torture — as part of the debate on the Military Commissions Act — that "may decrease the burden on him (Mukasey)."

In September 2006, Sen. Edward Kennedy, D-Mass., authored the amendment to the military tribunals bill that would have effectively defined waterboarding as torture and made it subject to Common Article 3 under the Geneva Conventions.

The amendment itself focused on conduct of other countries, but said: "should any United States person to whom the Geneva Conventions apply be subjected to any of the following acts, the United States would consider such act to constitute a punishable offense under common Article 3 ... ."

The amendment listed "forcing the person to be naked, perform sexual acts, or pose in a sexual manner; applying beatings, electric shocks, burns, or other forms of physical pain to the person; waterboarding the person; using dogs on the person; inducing hypothermia or heat injury in the person; conducting a mock execution of the person; and depriving the person of necessary food, water, or medical care."

The amendment failed to gain the needed 50 votes, failing 46-53. Specter and then-Sen. Lincoln Chafee of Rhode Island were the only Republicans to vote in favor. Sen. Ben Nelson, D-Neb., was the lone Democrat to oppose the measure.

Specter and Sen. Sheldon Whitehouse, D-R.I., a former U.S. attorney, have both indicated they are weighing Mukasey's response on waterboarding against the fact that the Justice Department has had only an acting attorney general for the last six weeks. Several members have said they are satisfied with Mukasey's answers about the independence he would exert from the White House.

"I'm considering the overall issue here. The department is in dire straits, and it's not getting any better," Specter said.

Asked about how important it is for Mukasey to equate waterboarding with torture, Sen. Olympia Snowe, R-Maine, a member of the Senate Intelligence Committee, said: "Absolutely it's critical. He plays a pivotal role. ... I don't see why he couldn't answer the question more straight forwardly." She added that waterboarding is torture.

Sen. Dianne Feinstein, D-Calif. — who sits on both the Intelligence and Judiciary committees — said she will introduce broad legislation soon that will "codify once and for all that all departments of the federal government — whether you're military, or CIA or FBI or any special elite unit — are subject to use only those interrogation techniques that are part of the military field manual."

Feinstein went on to say: "I really think that overall, the Army Field Manual will bring about better results than interrogation techniques, even those now in use, without going into it further," she said, adding that she did not want to discuss classified matters.

"I have substantial puzzlement why his (Mukasey's) personal view isn't, 'Yes, it constitutes torture,'" Feinstein said.

But to be sure, Mukasey still has strong supporters on the committee, Graham, one of the authors of the detainee treatment and tribunal legislation, said Mukasey "doesn't need to be issuing legal opinions about programs he's not aware of, but he can comment on the technique from his own personal view. I think it's important for him to comment on the technique with a general view of whether it's in bounds or not and his own view of it, but reserve the right to look at facts and circumstances."

Sen. Sam Brownback, R-Kansas, on Tuesday said Mukasey "on the key issues of our day, the security of our country, is one of the best legal experts in a practical sense."

He said critics are "being extraordinarily picky. This is an important topic, no question about it, but the core issue here is the security of the country and the intelligence-gathering operation balanced off against civil liberties for the nation.

"Here is a guy who is a legal expert on it and handled it in practical cases. This is a man well-qualified and very talented for the era he would be put into office," Brownback said.

Sen. Tom Coburn, R-Okla., also said Mukasey's answers satisfied him.

"I didn't take anything he said to give me great concern that he couldn't lead the Justice Department. And now with 10 out of 15 of the top positions empty, to not even bring him up for a vote to me seems that we are abandoning our duties," Coburn said.

Sen. John Cornyn, R-Texas, reduced critics' problems to a political issue.

"I think this is just more posturing for the hard left and it's unfortunate," he said.

FOX News' Trish Turner and Mike Majchrowitz contributed to this report.