In a statement on Friday announcing the development, Linda A. Klein, the group’s president, said it had provided prenomination evaluations of potential judicial candidates to every administration since that of Dwight D. Eisenhower, with the sole exception of that of George W. Bush.
The bar association recently gave its highest rating to Judge Neil M. Gorsuch, President Trump’s Supreme Court nominee. The administration and Republican senators have repeatedly relied on the endorsement as proof that Judge Gorsuch deserved to be confirmed.
Donald F. McGahn II, the White House counsel, notified the group of the decision to cut them out of the vetting process in a March 17 letter to Ms. Klein.
“Like previous administrations,” Mr. McGahn wrote, “we will release information regarding each nominee in a manner that provides equal access to all interested groups. But we do not intend to give any professional organizations special access to our nominees.”
Some studies have concluded that the bar association, a private trade group that often takes liberal positions, tends to favor the nominees of Democratic presidents.
In her statement, Ms. Klein said the A.B.A. had conducted “an objective, nonpartisan review of the professional competence, integrity and judicial temperament of those who would have lifetime appointments to our federal courts.”
In an interview on Friday, Judge Kozinski said his ratings had been particularly low. “I don’t see why one group in particular, all locked up by essentially big-firm lawyers, should have this special status,” he said.
Among other nominees of Republican presidents, Justice Clarence Thomas was given a split rating of “qualified” and “not qualified.” Judge Robert H. Bork, whose nomination was rejected by the Senate in 1987, received a curious decision, with the majority calling him “well qualified,” but four members saying he was “unqualified.”
Republicans have had less to complain about recently. Mr. Bush’s two appointees to the Supreme Court, Chief Justice John G. Roberts Jr. and Justice Samuel A. Alito Jr., both received the group’s highest rating.
“We do not give the ‘well qualified’ rating lightly,” Nancy Scott Degan, an official of the bar association, said last week at Judge Gorsuch’s confirmation hearings. The group had also given its highest rating to Judge Merrick B. Garland, President Barack Obama’s Supreme Court pick, whose confirmation proceedings were blocked by Senate Republicans.
Ms. Degan said the group’s evaluations were limited to candidates’ integrity, professional competence and judicial temperament. Ideology and politics were out of bounds, she said.
Amy Steigerwalt, a political scientist at Georgia State who has studied the A.B.A.’s role in judicial nominations, said she was surprised by the move. “There does seem to be in this administration a backing away from the establishment,” she said.
Ms. Klein of the A.B.A. said her group “will continue to provide its objective evaluations to the Senate Judiciary Committee as part of the judicial confirmation process.”