Top Republican donors were among the thousands who attended the GOP debate Thursday at the North Charleston Coliseum in South Carolina. (Rainier Ehrhardt/AP)

About 1 a.m., long after the GOP presidential contenders had finally filed off the stage of the North Charleston Coliseum, the Republican National Committee’s post-debate party was still going strong.

Top party donors jammed into the ballroom of an upscale hotel in the city’s historic downtown, milling around a long buffet table piled with pulled-pork sandwiches, baby shrimp, macaroni and cheese, and ice cream sundaes. They buzzed about the sharp jousting between Donald Trump and Ted Cruz, caught up on campaign gossip, and made plans to see one another at one of the upcoming forums in Iowa, New Hampshire or Florida.

The outsize spectacle of this primary season’s Republican debates has made the events hot-ticket items for wealthy donors, who are flocking to them as if they were political bowl games.

“It’s like Old Home Week,” said Ray Washburne, the national finance chair for New Jersey Gov. Chris Christie’s campaign, who has been to all six GOP primary debates held so far. “Even though we’re all on different sides, it’s fun to meet up.”

Major fundraisers and top contributors fly in on private jets and gather in hotel suites before start time, marveling over the latest twists in the race. Once inside the venue, they snap selfies in front of the stage. They anxiously root for their favored candidates, swapping text messages with friends as the jabs fly back and forth.

Leora Levy, of Greenwich, Conn., a fundraiser for former governor Jeb Bush’s campaign, has attended four GOP debates so far this cycle. (Mic Smith/For The Washington Post)

“It’s the same thing as going to a football game,” said Foster Friess, the Wyoming-based financial investor who was among the heavy hitters in the audience for Thursday night’s debate in Charleston. “If you’re in the crowd, you can hear the cheers, unfiltered by microphones. The chemistry is so much more exciting.”

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The crowded field of candidates — each with their own constellation of rich backers — has meant a heavier donor presence at the GOP forums than at the smaller Democratic ones, where Sen. Bernie Sanders (Vt.) repeatedly declares his independence from millionaires and billionaires.

The regular attendance by wealthy contributors is also due in part to the control that the RNC exerted over the primary debates this cycle. The national party doles out the tickets, unlike in past years when admittance was in the hands of the television networks and local parties hosting the forums.

The RNC allocates blocks of tickets to individual campaigns, volunteers and activists. But a chunk is also set aside for top money players such as Team 100 contributors, who have given the annual maximum of $33,400 to the party, according to people familiar with the arrangements.

“Because of the historic number of talented and diverse Republican candidates running this cycle, our voters, activists and donors are excited to be part of the process that will elect the next Republican president,” said the RNC’s communications director, Sean Spicer.

The campaigns also set aside debate seats for their biggest financial backers, arranging receptions and briefings for them on debate days.

“I heard people here saying, ‘I’ve been to three, how many have you been to?’ ” said Washington lobbyist and GOP fundraiser Richard Hohlt. “There are people who are almost debate groupies.”

Aside from the social aspect, the debates serve a practical purpose for donors seeking to be deeply immersed in the mechanics of the campaigns they’re helping finance. Attending the forums gives them a chance to make an in-person assessment of the field — and gauge how others are reacting.

“On TV, you don’t feel the audience around you,” said Virginia developer Bob Pence, a fundraiser for Sen. Marco Rubio (Fla.) who traveled to Cleveland; Simi Valley, Calif.; and Las Vegas for debates this season. “When you’re there with two or three thousand people, you hear what people are saying. It’s a learning moment, to glean what other people are thinking.”

For New York venture capitalist Ken Abramowitz, who has made contributions to multiple candidates, the appeal is less the main event and more the private gatherings afterward, where he tries to offer some feedback to the White House hopefuls.

“I like to give them a word of advice if they said something during the debate I thought was wrong,” said Abramowitz, who said he managed to buttonhole former Florida governor Jeb Bush, Wisconsin Gov. Scott Walker and former Arkansas governor Mike Huckabee at receptions after the first debate in August in Cleveland. “I will point that out to them — not in a critical manner, but a friendly manner, to help them.”

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The donor scrutiny was particularly intense at last month’s forum at the Venetian resort in Las Vegas. Sitting front and center in the audience were billionaire casino magnate Sheldon Adelson and his wife, Miriam, who have not publicly declared their support for a candidate. Seated nearby were Oklahoma oil-and-gas ­entrepreneur Harold Hamm and two major Rubio backers, New York hedge-fund manager Paul Singer and North Carolina retail executive Art Pope.

Chicago Cubs co-owner Todd Ricketts was also on hand, attending his third debate of the election season, as was Dallas investor Doug Deason, a Cruz supporter who flew in for his first.

Not all were sold on the experience.

“I thought it was boring,” said Deason, noting that the guests had to sit through the “undercard” forum of lower-tier candidates in order to have a seat for the main debate. “They didn’t serve alcohol, which wasn’t much fun. And you can’t really understand what they’re saying. Watching at home, on television, I can rewind it. Or if I get frustrated, I can pause it and go outside.”

Veteran debate attendees know it helps to come prepared.

The Charleston event was the fourth of the season for Leora Levy, a fundraiser for Bush’s campaign who lives in Greenwich, Conn. She was ready with protein bars and a stash of emergency chocolate to make it through the two hours between the undercard debate and the main event.

The long wait is worth it, she said. “When you’re there in person, you can see how the person is acting, even when they’re not on camera,” Levy said. “I just find it more revealing.”

While they waited, guests munched on popcorn and cookies in snacks bags provided by the RNC. “Showtime!” tweeted Bush fundraiser Anthony Scaramucci, sharing a photo of himself with New York Jets owner Woody Johnson, Bush’s finance chairman.

Seated on the floor in Row K was Andrew Sabin, a Bush backer who owns a New York-based precious-metals refining business and had flown his private jet up from Key Largo for the night.

“It’s just an hour and a half away, so I figured, ‘Why not?’ ” said Sabin, who went up to the stage to say hello to Bush during a commercial break.

He was pleased with the former governor’s performance. Bush “was the only one who knows what he’s talking about,” Sabin said.

Plus, the zingers flying on stage made for an entertaining night. “It’s like a reality TV show,” Sabin exclaimed at the end of the night.

The event was not as gratifying for Friess, a backer of former senator Rick Santorum (Pa.), who has been relegated to the early undercard forums. The sparring in the main event did not impress him.

“It turns into a media ratings game to see who said what,” Friess said. “I was pretty disappointed in the tenor.”

But he enjoyed the RNC’s after-party, where he stayed until 3 a.m., catching up with friends.

“We closed it down,” Friess said. “In my older years, I’ve become kind of a party boy.”