MIAMI — The loneliest man in Miami holds a rough-cut wooden stick with a sign attached to the top that reads “O’Rourke campaign.”

He glances left to right, ever so awkwardly. Shoulder-mounted cameras and notebook-wielding scribblers flood past him, barely taking notice of his dreary isolation in the strange, ruthlessly culling dance of the post-debate spin room, where operatives try to put the best gloss on even the most tarnished performances.

The journalistic swarm pursues Julián Castro, the former HUD secretary whose feistiness onstage during the opening night of the two-day Democratic presidential debate here has everyone buzzing about a breakout performance — that is until everyone buzzes ever more urgently on Night 2 when Sen. Kamala Harris of California gets even feistier.

Thursday night’s biggest casualty — former vice president Joe Biden — didn’t even bother to show his face after his halting, befuddled and roundly panned performance. Instead, Biden dispatched a small army of spinmeisters with gold-plated Beltway credentials, led by former Obama White House communications guru Anita Dunn, who had a lot to clean up.

The horde demanded to know more about the signature exchange of the night — in which Harris, who is black, spoke with emotion about being bused to school in a different neighborhood and accused Biden of not being supportive of the initiatives that many black activists praised for allowing young African American students to attend better schools. Biden responded by parsing, saying that he didn’t oppose busing, he only opposed busing mandated by the federal government instead of being decided by local governments.

“The reality of this is these are all things that were known when Vice President Biden was chosen to be Barack Obama’s running mate,” Dunn said. “The American people know Joe Biden and they know what his values are.”

Dunn, managing director of one of Washington’s most high-powered communications firms, SKDKnickerbocker, is a master of this particular difficult art. She shifted from defending Biden’s stumbles to trying to implant an idea, an alternate interpretation of what the horde had thought it had seen.

“And I think what you saw tonight on the stage was someone who wants to lead this country, as he said in his closing statement, he wants to lead this country forward because the current administration we have is one that pits people against other people, group against group, that has hollowed out the backbone of the American middle class, and that Joe Biden is running because he wants to move this country forward, and he believes that we can.”

Classic spin. As canned as Spam, but served up so economically you might just buy it.

The horde in the spin room — a cavernous expanse that is usually the backstage of Miami's downtown opera house — makes snap decisions. It anoints champions and diagnoses terminal illnesses in campaigns barely underway, campaigns that may or may not exist the next time the field gathers for a debate. Over two sweltering nights, the panorama of modern American politicking was on full and florid display — fringe candidates sharing a stage with powerhouses, Cuban exiles out on the sidewalk warning that socialism is nigh, a food truck delivering free blue ice cream cones courtesy of Biden, and an anxious, sleep-deprived traveling band of professional political handlers whose nights end in the sort of scruffy dive bars that stay open well into the wee hours.

It’s long past 1 a.m. after the first round of the debate by the time Tim Ryan, the Ohio congressman, strolls into Mike’s, an Irish bar on the ninth floor of a downtown condo building, with a national news reporter and Lis Smith, the communication guru for one of Ryan’s rivals, South Bend, Ind., Mayor Pete Buttigieg.

“I could only find two bars open in Youngstown now,” Ryan quips. “One of them would be the Italian club.”

Smith orders a Bud Light, then slides into a side table with a couple other campaign operatives and a reporter or two. The joint is too loud for normal conversation, so she and Ryan spend much of the evening leaning in close to each other to be heard. At the tables around them, seats fill with operatives for another candidate, former Maryland congressman John Delaney, and for Massachusetts Sen. Elizabeth Warren, who occupied center stage on opening night by virtue of her elevated position in the polls.

The cross-pollination is a little understood reality of the primary scrums. Today’s rival camps may be tomorrow’s teammates. As campaigns fizzle, some of their staffers will be absorbed by the candidates who haven’t been voted off the island. Today’s warrior on behalf of Delaney or New York Mayor Bill DeBlasio or Tulsi Gabbard, the congresswoman from Hawaii, might be tomorrow’s mouthpiece for whomever survives the unforgiving early stages of the race. Today’s candidate might be tomorrow’s endorser of a former rival.

Parachuting 20 presidential candidates into one place for two days of debating turns the city into something like a mini-convention. Side trips are a must. Former Texas congressman Beto O’Rourke announces plans to visit a notorious migrant detention center in Homestead, outside the city, on Thursday. Before he can get there, Warren swoops down to Homestead on Wednesday, climbing a ladder to peer into the facility. . Harris lays plans to visit on Friday after the debates end. Homestead converts into shorthand for an immigration policy pilgrimage.

The millions of Americans who tune into the stylized two-hour Q&A sessions miss much of the jostling and positioning that happens off camera, after the main event.

The candidates enter the opera house through a side door that swings open fast and hard, spilling them into the blinding glare of television lights that illuminate a narrow walkway between metal barriers reminiscent of the chute that disgorges bronc-riding cowboys at a rodeo. The chute is the first measure of the horde’s pronouncements. On Wednesday night, the network producers and anchors draped along the full length of the barriers won’t let Castro take a step without cajoling him to stop and talk about how he confronted his fellow Texan, O’Rourke, on immigration policy, admonishing the former congressman and erstwhile glossy-magazine cover boy to “do his homework” on immigration policy.

Delaney, languishing near the bottom of the polls, glides through the chute in a flash. Hardly anyone is interested.

But O’Rourke —not so long ago a near-upset winner in a red-state Senate race and that most accessible of rising stars — had yet to emerge through the swing door. The night before he’d dined at a corner table in the hip locals joint just outside downtown called Mignonette. He’d been spotted that morning out for a run in the punishing Miami heat. It was hard to miss him. And then suddenly it was hard to find him.

When he finally emerged, long after the other candidates, he was quickly squired to a television interview with MSNBC’s Chris Matthews. Then, instead of plunging into the spin room where Cory Booker, the New Jersey senator who had wowed the crowd with his stories about one of his neighbors in Newark being shot to death, was feasting on attention (and Castro seemed to have all the time in the world to talk), O’Rourke made for the rodeo chute. But his path was blocked, and he had little choice but to stop and answer questions from a swarm that seemed more intent on devouring a carcass than on crowning a contender.

Outside, several dozen loud demonstrators gathered on opposite sides of the street in the shadow of the 570,000-square-foot Adrienne Arsht Center for the Performing Arts, a complex that vaguely calls to mind two enormous sand castles collapsing in the face of a stiff ocean breeze. Biden's performance inside the arena is generating few fans, but the ice cream truck offering "Biden Cones" is a hit. The proprietor, Miss Froztee, says she was told to make blue ice cream — to pay homage to the Democratic Party. By some formula she will not reveal, she made raspberry-flavored ice cream blue.

Alas, even that feels like a bit of a misstep for the Biden campaign, evoking an embarrassing detail in a Washington Post report this week about the wealth the former vice president who once styled himself “Middle-Class Joe” has accumulated since leaving office. Among the dishy details: Biden’s speaking contracts required that he be served the same Italian meal, which always ended with sorbet — and the flavor he demanded was . . . raspberry.

A tall, ruggedly built man crossed over from the pro-Trump side of the street and returned with a cone piled high with the blue ice cream.

“I got free pinko ice cream, but it’s blue,” he growled to his pals.

Between licks, he pointed out that he is a “secret person.”

“I’m not here,” he warned.

The air is scented by wafts of smoke emanating from a kielbasa-sized cigar called the La Bomba “F-bomb.” Somewhere in that sweet-scented cloud, Julio Martinez, a former mayor of Hialeah, sweated through his shirt, hoisting a flag with the image of an AR-15 assault rifle and the words: “Come and take it.”

At home, Martinez said, he has two AR-15s.

A few steps away, Martie Mees, a leader in the Republican Party of Miami-Dade County who was born in Havana but immigrated to the United States before Fidel Castro took power, is showing off pictures of the cake she ordered for her annual birthday party for her favorite occupant of 1600 Pennsylvania Ave. The inscription, spelled out in frosting says: “Happy birthday beloved President Trump.” This year she had a flamenco dancer perform.

Their refrain today is their eternal refrain. They want to lay over the politics of Cuban exiles onto the politics of the United States. They hate what the country they fled has become. They’re certain that Democrats will turn their new country into a facsimile on a larger scale.

Behind him, a woman holds a sign that reads “Pocahontas,” invoking Trump’s nickname for Elizabeth Warren, who struggled to explain why she had once claimed Native American ancestry. “You are an insult to those of us who are Native Americans.”

Of what tribe is she a member?

“The Cuban tribe,” she says.

The senator from Vermont irks them most.

“Sander,” one man’s sign reads, in a reference to Bernie Sanders, a declared democratic socialist. “I’m a socialism victim.”

The man with the Bomba cigar starts yelling as a group of Sanders supporters slips past: “You can’t be that stupid! Read an economics textbook — Milton Friedman!”

None of this pro-Trump clatter reaches through the thick walls of the Arsht Center. Inside, in the waning hours of the two-day spectacle, another lonely man holding the O’Rourke sign has taken up his post, with a hopeful look on his face. He spends much of the evening by himself.