Trump does not defend our democracy from the ruinous consequences of conspiracy thinking. Instead, he embraces such thinking. A conspiracy theory—birtherism—was his pathway to power, and, in office, he warns of the threat of the “deep state” with the ferocity of a QAnon disciple. He has even begun to question the official coronavirus death toll, which he sees as evidence of a dark plot against him. How is he different from Alex Jones, from the conspiracy manufacturers of Russia and the Middle East?

He lives in the White House. That is one main difference.

This improbable question—how did a person with a weakness for conspiratorial thinking achieve the presidency?—might be among the most consequential of the coming election, which is not merely a political contest, but a referendum on enlightenment values and on reality itself.

Nonsense is nonsense, except when it kills. And conspiracy thinking, especially when advanced by the president of the United States, is an existential threat.