By Andrew Chung (Reuters) -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. In 2015, the man who would become the chief executive of the United States assailed the integrity of its chief justice,

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.