The chief justice has often expressed dismay when judges are referred to by political affiliation. He has also observed since 2010, with the retirement of liberal Justice John Paul Stevens, an appointee of Republican President Gerald Ford, that it may be more difficult to convince the public of justices’ impartiality from politics.

Since Stevens was succeeded by Obama-appointee Elena Kagan, and continuing with Trump’s choice of Kavanaugh, the court’s five conservative justices were named by Republican presidents and the four liberals — often relegated to the dissent — were named by Democratic presidents.

With Kennedy’s retirement, Roberts is now ideologically at the middle of the court, and he may be inclined to hedge his own conservative instincts to steady the bench and avoid more polarization.