The decision by Sens. Charles Schumer and Dianne Feinstein came shortly after the chairman of the committee, Patrick Leahy, D-Vt., announced he would vote against Mukasey, a former federal judge.
"This is an extremely difficult decision," Schumer said in a statement, adding that Mukasey "is not my ideal choice."
In announcing her support for Mukasey, Feinstein, D-Calif., said "first and foremost, Michael Mukasey is not Alberto Gonzales," referring to the former attorney general who resigned in September after months of questions about his honesty.
Just two weeks ago, Leahy predicted smooth sailing for Mukasey towards confirmation, but he now becomes the fifth Democrat on his committee to say he'll vote against Mukasey after the nominee seemed to do some serious fudging on the definition of torture and President Bush's obligation to always follow the law, reports CBS News correspondent Bob Fuss.
The nominee refused to say that waterboarding, an interrogation technique that simulates drowning, is torture and therefore illegal.
But with nine Republicans on the panel, Schumer's and Feinstein's support for Mukasey virtually guarantees that a majority of the committee will recommend his confirmation when it votes on it next Tuesday.
Leaders in both parties have said they expect Mukasey to get at least 70 votes when the full, 100-member Senate votes on his confirmation. But Majority Leader Harry Reid, D-Nev., had said he would not bring it up for a vote without Judiciary Committee action first.
Schumer's announcement followed a private meeting Friday with Mukasey to discuss waterboarding.
"I deeply oppose it," Schumer said of waterboarding. "Unfortunately, this nominee, indeed any proposed by President Bush, will not agree with this. I am, however, confident that this nominee would enforce a law that bans waterboarding."
Schumer, who was Mukasey's chief Democratic sponsor, said the retired judge told him that if Congress passes a law banning waterboarding "the president would have absolutely no legal authority to ignore such a law." Schumer said Mukasey said he would enforce any congressional ban the controversial interrogation method.
Torture is considered a war crime by the international community and waterboarding has been banned by the U.S. military, but CIA interrogators are believed to have used the technique on terror detainees as recently as a few years ago.
Mukasey has called waterboarding personally "repugnant," and in a letter to senators this week said he did not know enough about how it has been used to define it as torture. He also said he thought it would be irresponsible to discuss it since doing so could make interrogators and other government officials vulnerable to lawsuits.
Early Friday, President Bush renewed his plea for Mukasey's confirmation.
"He's a good man. He's a fair man. He's an independent man, and he's plenty qualified to be attorney general," Bush said of Mukasey, just after landing in Columbia, S.C., on his way to a political fundraiser and to give a speech at Fort Jackson.
On Thursday, Bush had warned that the Justice Department would go without a leader in a time of war if Democrats thwarted Mukasey.
Bush also said that if the Judiciary Committee were to block Mukasey because of his noncommittal stance on the legality of waterboarding, it would set a new standard for confirmation that could not be met by any responsible nominee for attorney general.