California-based appeals court has been thorn in Trump's side

The president regularly belittles the 9th Circuit, as he did on Friday after the court's ruling preserving the Deferred Action for Childhood Arrivals (DACA) program.

"The DACA will now hopefully go to the Supreme Court where it will be given a fair decision," Trump told reporters.

Trump already has appointed two justices to the nine-member Supreme Court, solidifying its 5-4 conservative majority.

The 9th circuit has 16 judges who were appointed by Democratic presidents and seven who were named by Republican presidents. Democratic presidents tend to appoint more liberal jurists while Republican presidents favor more conservatives judges.

It is one of the series of powerful regional federal appeals courts that are one step below the Supreme Court. These circuit courts often provide the last word in a legal dispute because the Supreme Court hears only a limited number of cases.

The 9th Circuit hears appeals in federal cases spanning a huge region in terms of both geography and population, covering the states of Alaska, Arizona, California, Hawaii, Idaho, Montana, Nevada, Oregon and Washington.

Trump already has named two judges to the 9th Circuit, with six other vacancies waiting to be filled. Trump will not be able to create a conservative majority on the 9th Circuit, however, without additional vacancies caused when actively presiding judges retire.

Aided by fellow Republicans in the U.S. Senate, Trump has made it a top priority to rapidly appoint judges in a bid to make the federal judiciary more conservative.

Trump has suggested his policies do not get a fair shake in the 9th Circuit and has touted the idea of breaking up that court. Trump last year decried the 9th Circuit's "ridiculous" ruling on the travel ban, and said that court has "a terrible record of being overturned" by the Supreme Court - an often-made charge that the 9th Circuit's chief judge took issue with in congressional testimony.