Chief Justice John Roberts Jr. rarely loses his temper.

Since his days as a top Supreme Court advocate in the 1990s and early 2000s, he has been known as a calm, even-tempered voice at the court. Asked in 2000 why he was not more impassioned in his delivery, he told this reporter, “Impassioned rhetoric doesn’t work with the Supreme Court. If it did, I’d become impassioned.”