Still, interest in the event was high. About 1.1 million people registered to attend, forcing aides to begin making plans to stage an added outdoor event. Aides knew the 1.1 million figure was inflated: After sorting through the sign-ups — a process that included looking at registrants’ voting histories — they determined that about 300,000 were fake.

To winnow down the likely audience further, advisers estimated that only between 200,000 and 300,000 people lived within immediate driving distance. Worst-case scenario, they concluded, was an audience of about 60,000.

But when they woke up Saturday morning, Trump advisers realized things were going downhill. Protesters were convening outside the arena. News emerged that a half-dozen advance staffers had tested positive for coronavirus, a revelation that angered the president ahead of his departure for Oklahoma and further amplified fears that the event could spread the disease. Hours before the rally was to get underway, it became clear to the president’s lieutenants that a debacle was underway and that there would be a patchwork of empty seats.

Making matters worse for the campaign was its initial declaration that 1 million people had signed up to see Trump in Tulsa, a boast that was now destined to fall on its face.