In his year-end report, Roberts called on President Barack Obama and the Senate Friday to address what he called "the persistent problem of judicial vacancies," The New York Times reported.
Citing the Administrative Office of the United States Courts, the newspaper said there are 96 federal court vacancies.
Roberts noted that the Senate has confirmed 62 of Obama's federal court nominees, including 19 who were recently confirmed, but he said the number of vacancies that remain are causing "acute difficulties in some judicial districts."
"There remains an urgent need for the political branches to find a long-term solution to this recurring problem," he said.
Roberts' admonition resembles a similar exhortation in 1998 by William Rehnquist, chief justice at the time, who criticized Senate inaction on judicial nominations submitted by President Bill Clinton, the Times said.
"We do not comment on the merits of individual nominees," Roberts said in his report. "That is as it should be. The judiciary must respect the constitutional prerogatives of the president and Congress in the same way that the judiciary expects respect for its constitutional role."
He suggested partisan politics plays a role in the relatively slow pace of judicial nominee confirmation.
"Each political party has found it easy to turn on a dime from decrying to defending the blocking of judicial nominations, depending on their changing political fortunes," he said.
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