If judges were not political, the Kavanaugh confirmation circus would never have happened. Presidential campaigns often use the promise or threat of who might be appointed to courts as part of their marketing strategies. As do political parties.
Roberts’ statement is utterly dishonest. And he knows it.
Judges do not have any authority to rule on items for which there is no legislated or constitutional law.
Judges do not adjudicate disagreements between the branches of US government. To do so would put them _above_ the other branches. They are an equal branch. Not the final arbiter of inter-branch disputes.
Judges who act outside of their lawful authority need jail time.