Sen. Jeff Flake, R-Arizona, took his efforts to split the U.S. Court of Appeals for the Ninth Circuit on the road Thursday as he chaired a hearing of the Senate Judiciary's Subcommittee on Privacy, Technology and the Law in Phoenix.

Flake, who faces a Republican primary challenge in his bid for re-election to the U.S. Senate, was the only member of the subcommittee in attendance, although the hearing did feature four Ninth Circuit judges. Judges Diarmuid O'Scannlain and Richard Tallman favored the split, and Chief Judge Sidney Thomas and Judge Mary Schroeder opposed it.

The threat of a split is as real as it has been in years, or perhaps ever, with Republicans controlling both chambers of Congress and President Donald Trump, a vocal critic of the Ninth Circuit, in the White House.