Mr. Trump, who turned 72 on June 14, was at one of his other properties — his Virginia golf course — on Sunday afternoon, but that hardly dampened the crowd’s enthusiasm.

The event kicked off with a prayer for the president: “We ask God for protection of this man” and “We lift him up, Lord, not that he is perfect.” Then it moved swiftly toward its centerpiece, a runway fashion show of the work of Andre Soriano, the designer shunned by the fashion world after he designed the “Make America Great Again” gown worn by the singer Joy Villa to the 2017 Grammy Awards.

Female pro-Trump organizers and donors modeled some 50 gowns, which, like a fireworks display, grew shinier and more elaborate toward the finales. At one key moment, a woman in a flowing, black and white, Asian-style costume appeared. As martial-sounding music played, she walked the runway with arms outstretched, carrying what looked like a red velvet and gilded Valentine’s Day candy box. The women cheered as she paused, lifting the box to the heavens.