“So we’re going to the fight,” Mr. Trump said. “We have lots of fights going around the world, and I think we have a lot of good news coming soon about some of those fights, and we’ll see how it goes. But it’s been a it’s been an interesting weekend. I think we have some pretty good news coming on some of the conflicts.”

But the scene on Saturday was emblematic of a president who is increasingly emboldened, brazen and encouraging of displays of force to carry out his agenda, particularly on immigration and crime.

Mr. Trump walked into the Kaseya Center to the booming sounds of the Kid Rock song “American Bad Ass” and to sustained, thunderous applause from the crowd.... See more