Yet by any measure the rest of the Bannon Presidency was a colossal failure. The former Breitbart publisher was a major source of White House dysfunction as he brought his brawling campaign style indoors. His Manichean, almost apocalyptic view of politics—us vs. them, patriots vs. “globalists,” America has only a short time to avoid self-destruction—might work in an election campaign. It isn’t suitable to building a coalition to govern.

Mr. Bannon presided over some of Mr. Trump’s biggest debacles, starting with the rushed and legally unvetted travel ban. That began his Presidency with a needlessly polarizing debate when the White House should have been reaching out to persuadable Democrats and wary Republicans, and it set up Mr. Trump for a legal and political defeat.