Blacklock is replacing retired Chief Justice Nathan Hecht, while Abbott's legal adviser James Sullivan takes the open spot on the bench.

Supreme Court Chief Justice John Roberts warned on Tuesday that the United States must continue to uphold "judicial independence."

Blacklock replaces Nathan Hecht, the longest serving justice on the high court. Gov. Greg Abbott also appointed his general counsel, James Sullivan, to the bench.

Arkansas Supreme Court Chief Justice Karen Baker on Wednesday declared invalid two per curiam orders her fellow justices issued in the past week, the latest development in an ongoing dispute over the scope of her authority.

Abbott appointed Justice Jimmy Blacklock to serve as chief justice on the Supreme Court of Texas, the governor's office announced Monday.