Outside, posters of President Obama and the first lady were the only signs that Eastern Bloc was closed for a private party. To some regulars of the grungy gay bar in Manhattan’s East Village, the $100 minimum cover charge seemed too pricey for a Saturday night.

But for an Obama campaign fundraiser, the entrance fee was relatively modest, unlike some of the boisterous dancers at the “GoGo for Obama” event. The fundraiser, hosted by a gaggle of models, fashion editors and socialites, is just one of hundreds of such small, grass-roots events organized by individual donors and held throughout campaign season in private homes or during backyard barbecues. Saturday’s soiree proved that with broad support from new interest groups comes a new breed of campaign fundraiser — a kind that might make some buttoned-up campaign types wince.

The crowd of about 150 Obama supporters was cordial and relaxed, a mix of friends and fashion types, partying alongside male dancers wearing Obama ’08 boxer briefs (or, as one did, an American flag-themed thong) stuffed with the requisite $1 bills. (Only door proceeds went to the reelection fund; dancers kept their tips.)

In this billion-dollar-plus election cycle, online fundraising and grass-roots events matter greatly to the Obama campaign, which has struggled to compete with Mitt Romney’s fundraising among high-dollar supporters. While the Romney campaign hasn’t put the same emphasis on small donors, the Obama campaign relies on them and last week announced it has a record-breaking donor base of 3.1 million individuals, surpassing Obama’s total from 2008. Two million of these donors have given less than $25.

The Obama campaign has promoted its “Grassroots Fundraiser” platform online, encouraging donors to reach out to friends and connect directly to the campaign’s Web site. In an instructional video on YouTube, Betsy Hoover, director of online organizing for Obama for America, emphasizes that “personalization is heavily encouraged.”In other words, donors can become creative — sometimes very creative.

Mickey Boardman, editorial director for New York’s independent Paper Magazine, helped to organize the Eastern Bloc fundraiser, which had a modest goal of raising $20,000. By midnight, when the dancers took to the poles, they’d collected more than $10,000. The host committee included Karen Elson, the model and ex-wife of White Stripes frontman Jack White; Derek Blasberg, Harper’s Bazaar editor-at-large, and Sean Avery, the retired professional ice hockey player. Blasberg’s own Harper’s Bazaar wrote that the fundraiser would show “D.C. how it’s done.”

“We do these parties for gay porn stars at Eastern Bloc whenever [they’re] in town from L.A.,” said Boardman. “It’s always a room of Village gays, socialites, porn stars, fashion people. . . . We thought, ‘Why don’t we do a go-go thing at Eastern Bloc for [Obama]?’ ”

Still, organizer Will Wikle said the group recognized that the event could make campaign organizers uncomfortable, so they toned down promotional materials. “We didn’t put a go-go boy on the invitation for that reason,” he said. “We didn’t want any Republicans to jump on it and view it as some sex party.”

And Wikle said the host committee was diligent in its two months of planning, working with Democratic officials to navigate campaign finance law, something that the organizers knew little about. Wikle said officials told the host committee it couldn’t have liquor sponsors or an open bar.

The go-go party highlights the fashion industry’s newfound interest in political fundraising. With Anna Wintour, the Vogue fashion editor, as a top Obama campaign bundler in 2012, many designers have followed her lead, designing for the campaign’s “Runway to Win” store and donating at smaller industry events such as “GoGo for Obama.”

“We’re not Anna Wintour,” said Marjorie Gubelmann, an organizer of the Eastern Bloc event. “We just wanted to throw a small party where our friends could have fun.”

So, was the campaign concerned about an event at a New York City gay bar featuring scantily clad dancers?

An Obama campaign spokeswoman said that keeping track of the many small events is next to impossible, so the campaign has adopted a model common in social media: It will look into any event that triggers complaints. No word yet on whether anyone’s complained about the go-go party.

T.W. Farnam contributed to this report from Washington.