From the president’s vantage point, his supporters looked like they were in cages. Their fingers curled around chain-link. Bellies smushed against butts. When their knees gave out, they sat on ponchos and muddy blankets and squares of wet cardboard. The air, scented by sodden socks and bug spray, sagged with humidity. When the breeze picked up, so did the sensation that everything was surrounded by a battalion of toilets. It was difficult to move, to escape, but then no one was trying to do so. They were grateful to be here, soaked by hours of drizzle, hugged by a lazy heat, waiting hours and hours for him, for the show. The president had invited them to express their love of country in a maze of corrals, on a truly crappy day of weather, but they didn’t feel like prisoners of pomp or slaves to circumstance but jubilant pilgrims thrilled to be counted as citizens of the “most just and virtuous republic ever conceived,” as the president put it.

Signs of distress were isolated. “CLOSE the CAMPS” said one sign, pressed against the fence toward the Lincoln Memorial, in reference to the squalid detention centers holding asylum-seeking migrants at the U.S.-Mexico border. Even if the letters were big enough for the president to read, his attention was on his teleprompter text. He was talking about conquering other planets.

“Someday soon,” President Trump declared from a dais of red carpet, “we will plant the American flag on Mars.”

The United States has turned 243 years old, which is adolescent for an empire (at least when compared with Rome). This might explain the national mood swings and infatuations, the cliques and the clumsiness, the tendency to bully or be bullied. It might explain why the 45th president wanted to fly a series of loud machines over the Mall, and why his haters wanted to fly a blimp of him as an infant, diapered and cranky. The blimp was inflated but never flew.

“Officials pulled the plug yesterday right when we were about to get helium,” grumbled Joe Kennedy, the blimp baby’s guardian, across the street from the World War II Memorial on Thursday morning. Armed with nearly a dozen sandbags, two turbine leaf blowers and one bike pump, eight sweaty volunteers unfurled the baby’s flattened skin and inflated it in parts: first, its tiny orange hands. Then its body, but only halfway, because the ears had to be filled before the body could be hoisted upright.

People had staked out spots around the Reflecting Pool by 9 a.m. — a full nine hours before the “Salute to America” program started — as the president himself arrived at his golf club in Sterling, Va. The earthbound blimp was fully inflated by 11. By midafternoon a slight but stubborn rainstorm settled over the capital and a wild assortment of Americans mingled in front of the White House. An irate New Yorker, a wolf tattoo on his biceps, shouted about how men have no rights anymore. A Bernie Sanders supporter with a GoPro on his shoulder debated people through a megaphone. Black-clad members of the Revolutionary Communist Organization set fire to an American flag. Tourists took selfies as if it were all perfectly natural.

Around the Reflecting Pool, in the hours before the president’s address, all was joyful and polite, if crowded and with limited views.

Normally a Trump rally is a Caucasian affair, but his “Salute to America” was a mishmash of ethnicities, languages, ages and intentions. Some were there for the spectacle. Some were there to bask in the president’s glory. Some were there as proud soldiers of QAnon, a baffling conspiracy theory that has flourished in the Trump era. Is it a religion that believes in secret cabals? Or a cult fantasizing about a coup?

“Think of it as a frequency, as a resonance,” said a QAnon guy from Atlanta who declined to give his name because he preferred to be “clandestine.” He had a shirt that said “TRUMP/JFK JR. 2020,” which was not meant to be interpreted as a literal ticket, he said, but as an occasion to liberate your mind from the usual parameters of, uh, life and death and the space-time continuum — maybe? They’re awfully nice people, these QAnon people here, and they love how President Trump has exposed the cracks in our accepted reality. They love how the light is shining through now.

A wall of dark clouds had begun building behind the Lincoln Memorial, sack-clothing the sunset. Trump’s exit from the White House was broadcast live to the crowd on giant screens. At 6:37 p.m. the presidential airplane buzzed the Mall, and then Trump walked onstage as if he had parachuted out. “Hello, America,” he said, though he was obscured from the crowd, fittingly, by the biggest TV screen of all.

The president, who loves to veer off script, stuck to it. He talked about Lewis and Clark, about Thomas Edison, about Apollo 11, about Sept. 11. He began to list the military accomplishments of the United States. A thousand feet to his left — beyond the memorial to the war he avoided with five draft deferments — was a statue of Albert Einstein, who said 90 years ago that “Nationalism is an infantile disease. It is the measles of mankind.”

As the military flyovers continued, 18-year-old Lucia Driessen ventured into the crowd blowing a whistle and holding a sign that said, “TRUMP DOESN’T CARE ABOUT YOU.” As a recent high school graduate who lives in the heavily Democratic capital, this was by far the largest number of Trump supporters she’d ever seen in person.

“Close the camps!” she yelled to attendees.

“U-S-A!” the crowd chanted back at her, and she cringed at the implication of the rejoinder. A B-2 stealth bomber, a jagged black terror, screamed overhead as the president held his chin high.

Trump’s been doing this kind of thing for years, though never with the U.S. military as his production team. In April 1990, when he opened the doomed Taj Mahal in Atlantic City, a 43-year-old Donald Trump arranged 5½ minutes of fireworks that were half-obscured by his own building, insinuated that he had cured a disabled guest of honor and — after his podium spittled theatrical fog — told the crowd to “have a nice life.” (His business would file for bankruptcy the following year.)

“There goes a good man,” a retired Coast Guardsman told The Washington Post at that long-ago event.

“It’s the media who projects him as a bigot or a racist,” retiree David Limina told The Post on Thursday, seated in a red camper chair.

Trump’s takeover of Washington’s holiday custom only went so far. Over on the other side of the Mall was the usual “Capitol Fourth” concert, where MAGA attire was scarce. Around 7 p.m. there was only one visible red hat, and it belonged to Wendy McHugh, 55, a registered nurse from Georgia. She took a circumspect view of the flyovers, the tanks, the president’s spin on the holiday.

“There’s going to be controversy. There’s going to be division, but that’s okay,” McHugh said. “That’s how we grow.”

Soon after Trump departed one side of the Mall, the concert began on the other side. In between, near the Washington Monument, was a wide expanse of families on blankets, waiting for the fireworks. The mood was peaceful, save for a single locus of agitation. By a portable statue of Trump sitting on a giant gold toilet, a handful of protesters blew whistles until their faces were flushed pink. They held signs that called attention to militarization, to the crisis at the border, to the precarious state of the rule of law. They were blowing whistles to puncture the picnic vibe, to signal that America was in crisis, that the empire was not maturing but devolving.

A nearby stack of speakers thundered with Sousa marches until TV star John Stamos kicked off the Capitol Fourth concert.

“I see a mosaic of different histories,” Stamos said, his voice piped all over the Mall, echoing into a garble.

A band of young white supremacists began to confront the protesters.

“All part of the fabric that makes us an American family,” went the disembodied voice of Stamos.

A scowling man in a MAGA hat put his fist near a protester’s face and turned his thumb down. Dusk was falling. The whistles reached a shrieking volume.

“Let’s love each other as citizens,” Stamos said, and the whistles kept going and going and going.

Travis DeShong and Terry Nguyen contributed to this report.