The hearings too often turn into "search and destroy" missions that ruin a person's reputation, said Mr. Bush in a speech to hundreds attending the 25th anniversary gala of The Federalist Society for Law and Public Policy Studies, in Washington, D.C.
The president chose what he hoped would be a friendly audience for his swipe at Democrats on Capitol Hill.
The Federalist Society, founded in the early years of the Reagan administration, is a conservative and libertarian group aimed at countering what it sees as the dominance of liberal ideology in law schools and elsewhere.
Dedicated to "reordering priorities within the legal system to place a premium on individual liberty, traditional values, and the rule of law," the Society counts some 20,000 lawyers, legal scholars and other legal professionals among its members.
Speaking to the group Thursday night, the president asked his audience to think back to a confirmation hearing that made news more than two years ago.
"When the wife of a distinguished jurist proudly attends his hearing and is brought to tears by ugly and unfounded insinuations that her husband is secretly is a bigot, we lose something," said President Bush.
Mr. Bush was referring to the Jan. 2005 confirmation hearing of Supreme Court Justice Samuel Alito, which left his wife, Martha-Ann Bomgardner, in tears after withering questions from Judiciary Committee Democrats.
During that hearing, GOP Sen. Lindsey Graham, in what was meant on his part to be a sympathetic question and a chance for Alito to defend his integrity, asked the then-nominee whether he was a "closet bigot."
The question then got a quick answer from Alito, whose wife began to cry as he shot back: "I'm not any kind of bigot."
There were no public questions for Alito Thursday night, who was on hand listening with the other dinner guests, as Mr. Bush complained that the Senate has failed to act on many of the nominees who have agreed to serve. He said senators are imposing a new standard in which nominees who have support of the majority of the Senate can be blocked by a minority of obstructionists.
"As a result, some judgeships go unfulfilled for years," said President Bush. "This leads to what is called judicial emergencies - vacancies that cause justice to be degraded or delayed. When Americans go to court, they deserve swift and fair answers, and the United States Senate should not stand in their way."
The Senate Judiciary Committee, led by Democrats, argues that the number of nominees pending is low. At the end of the Clinton administration, there were 26 circuit court vacancies because the Republicans did not confirm them in hopes that a Republican would take over the Oval Office.
Judiciary Committee Chairman Patrick Leahy, a Democrat, said there are 47 vacancies on both the district and circuit courts. President Bush has not nominated anyone for 26 of these 47 spots, according to the committee.
The White House said that historically, the Senate has confirmed an average of 17 circuit court judges in the final two years of the past three administrations. To date, only five circuit court judges have been confirmed.
"The Senate is no longer asking the right question, whether a nominee is someone who will uphold our Constitution and laws," said the president. "Instead, nominees are asked to guarantee specific outcomes of cases that might come before the court. If they refuse - as they should - they often find their nomination ends up in limbo instead of on the Senate floor."
President Bush's comments come amid mounting White House frustration over the president's stalled nominations to the federal courts. It also is part of a clear pattern by Mr. Bush to condemn Congress for not getting its work done, a strategy the White House believes gives it the upper hand.
Sen. Arlen Specter of Pennsylvania, the Judiciary Committee's ranking Republican, said President Bush's rhetoric was strong considering there still is hope for getting some nominees confirmed during the final year of Bush's presidency.
"A war of words is not productive," Specter said in a telephone interview.
While he said he understands President Bush's frustration, the White House must shoulder some of the blame, Specter said, noting that the president ignored five recommendations to fill a vacancy on the 4th U.S. Circuit Court of Appeals submitted to him by Virginia Sens. Jim Webb, a Democrat, and John Warner, a Republican.
"It's pretty fundamental that you listen to Republican senators," Specter said.