It was a sweltering Pennsylvania afternoon, hot enough to keep the medics busy as people wilted in the blazing sun. But the heat had hardly tempered the enthusiasm of tens of thousands of people on the Butler Farm Show grounds who were waiting for Donald Trump.

When he finally showed up, the crowd, saturated in Trump gear, shouted in collective excitement when he hit his usual marks. They booed when he mentioned U.S. President Joe Biden, jeered when he spoke of a rigged election and roared when he said he would make America great again.

Then there was a new sound. Pop.