For two of the most powerful men in the United States, Donald Trump and John Roberts, it has been a delicate dance from the start.

Roberts, as the head of the federal judiciary, has been facing mounting pressure to protect the courts from political interference. With a lifetime appointment, it remains to be seen whether the 70-year-old Chief Justice will take further steps to defend judicial independence as Trump continues his broadsides against the judiciary.

After Trump called for a judge’s impeachment, John Roberts expressed his disagreement with the Republican. It was not, however, the first time.