Trump’s very public interest in attendance figures distinguishes a campaign that benefits from perceptions of its own energy and momentum — and that refuses to hire pollsters, instead measuring its success by whatever numbers are at hand.

“He’s completely obsessed by it,” said a person familiar with Trump’s thinking about crowd estimates. “He believes that it is a real-time measure of how he’s doing. The fact that he has consistently drawn huge crowds is a matter of pride to him.”

According to a Trump associate, there are strategic reasons for touting, and inflating, crowd sizes. It telegraphs to voters that there is a movement behind Trump, and the buzz helps ensure that television cameras, the lifeblood of a campaign fueled by free media, continue to show up at his events.