When President Trump ticks off his accomplishments since taking office, he frequently mentions his aggressive makeover of a key sector of the federal judiciary — the circuit courts of appeal, where he has appointed 51 judges to lifetime jobs in three years.

In few places has the effect been felt more powerfully than in the sprawling 9th Circuit, which covers California and eight other states. Because of Trump’s success in filling vacancies, the San Francisco-based circuit, long dominated by Democratic appointees, has suddenly shifted to the right, with an even more pronounced tilt expected in the years ahead.