President Trump’s nomination of Washington, D.C., attorney Daniel Bress to the Ninth U.S. Circuit Court of Appeals in San Francisco was confirmed by the Senate on Tuesday on a party-line vote, giving Trump seven appointees to a court he has regularly denounced.

On the losing side of the 53-45 vote were California’s Democratic senators, Dianne Feinstein and Kamala Harris, who noted that the seat had been held by a Californian — Alex Kozinski, who retired last December after allegations of sexual misconduct by at least 15 female staffers — and would ordinarily be filled by a Californian. Bress, 40, was born in Hollister and grew up in Gilroy but has practiced law in Washington since 2008, mainly representing businesses.

“Bress is not a part of California’s legal community,” Feinstein and Harris said in a statement. Both members of the Senate Judiciary Committee, they criticized Republican leaders for discarding the “blue slip” tradition that committee chairmen from both parties had previously used to block confirmation hearings on judicial nominees if either home-state senator objected.

Another opponent, Kristine Lucius of the Leadership Conference on Civil and Human Rights, said Bress was part of a strategy by Trump and Senate Republicans “to mold the Ninth Circuit into a panel of young conservative ideologues.”

His defenders said Bress has California connections — he has been a member of the State Bar since 2008 — and stellar credentials. He graduated with honors from both Harvard University and the University of Virginia law school, was a law clerk for Supreme Court Justice Antonin Scalia, and has won several professional awards.

He joins a court that has been among the nation’s most liberal appellate circuits for 30 years. Trump has attacked the Ninth Circuit as “biased” and “hostile” for its rulings against his administration on such issues as immigration, birth control and his ban on U.S. entry from a group of mostly Muslim nations.

With Bress’ confirmation, the court will have 16 judges appointed by Democratic presidents, 12 by Republicans and one vacancy. Judges Carlos Bea and Jay Bybee, both Republican appointees with conservative records, have announced plans to transfer to senior status with reduced caseloads — Bea when his successor is confirmed, Bybee by the end of the year — creating two more vacancies for Trump to fill.

Although Democratic appointees will remain in the majority, “there will be increasing numbers of three-judge panels that will have two Republican appointees,” observed Carl Tobias, a University of Richmond law professor who tracks judicial nominations. He said the likelihood of a conservative majority would also increase on the 11-judge panels the court assembles for contentious cases in which a majority of the full court votes to reconsider the initial ruling.

Based on recent history, Tobias said, Senate Majority Leader Mitch McConnell, R-Ky., “will do everything possible to ensure that those seats are filled” during Trump’s current term. If a Democrat wins the presidency next year and Republicans keep control of the Senate, Tobias said, confirmations may return to the snail’s pace of 2015-16, when only two of President Barack Obama’s appellate nominees won Senate approval.

Bob Egelko is a San Francisco Chronicle staff writer. Email: begelko@sfchronicle.com Twitter: @BobEgelko