What is President Trump’s legacy?

Historians will face a daunting task in trying to assess Donald Trump’s presidency, which even the savviest of news consumers have struggled to follow.

It was clear from the very beginning that Trump would be a different kind of president than the U.S. had ever seen. By his second month in office, he had already signed his “Muslim ban” and seen his national security adviser resign in scandal, harbingers of the racial division and legal disputes that would be enduring themes throughout his time in office.

His first three years...