In his brief career as president and a candidate for president, Mr. Trump has attacked virtually every major institution in American life: Congress, the courts, Democrats, Republicans, the news media, the Justice Department, Hollywood, the military, NATO, the intelligence agencies, the cast of “Hamilton,” the cast of “Saturday Night Live,” the pope and now professional sports. He has attacked the Trump administration itself, or at least selected parts of it (see Sessions, Jeff), and even the United States of America (“you think our country’s so innocent?”).

“The Trump credo seems to be so many people to attack, so little time,” said Peter Wehner, a former strategic adviser to President George W. Bush and now a senior fellow at the Ethics and Public Policy Center.

Garry Wills, a historian who has studied other presidents, said, “No one else fires off omnidirectional personal insults in such fire-wheel fashion.” The exceptions seem to be President Vladimir V. Putin in Russia and white supremacists in Charlottesville, Va.