WASHINGTON — Chief Justice John G. Roberts Jr., reading for the majority on Tuesday morning, spoke clinically. Justice Stephen G. Breyer followed, working his way through his dissent mildly and analytically.

Then it was Justice Sonia Sotomayor’s turn.

Steely and unwavering, she began: “The United States of America is a nation built upon the promise of religious liberty. Our founders honored that core promise by embedding the principle of religious neutrality in the First Amendment.”

The crowded courthouse fell silent.

In upholding President Trump’s ban on travel from several predominantly Muslim countries, Justice Sotomayor continued, the Supreme Court had failed to “safeguard that fundamental principle.”

For the next 20 minutes, she remained resolute as she delivered an extraordinarily scorching dissent, skewering the court’s decision and condemning the ban as “harrowing” and “motivated by hostility and animus toward the Muslim faith.”