On the final day of the impeachment trial of President Bill Clinton, the presiding officer—Chief Justice William Rehnquist—offered a surprising message for the U.S. Senate. What will Chief Justice John Roberts Jr. say after the Trump impeachment trial ends?

Roberts, who took the presiding officer’s oath on Thursday, is just beginning his constitutional duty in the Senate trial, and he is appearing in a chamber riven with partisan distrust. Rehnquist served in a markedly different environment in which the Republican Senate majority leader worked closely with the Democratic leader to reach consensus on rules and proceedings.