Mr. Rendell, a gregarious figure of bipartisan popularity, asked one and all, “Have you ever seen a receiving line at a Pennsylvania Society reception?” He called Mr. Pileggi, who wore a business suit, white shirt and rep tie, the most powerful official in the state because of his ability to advance or block a governor’s agenda. “If you do any business in Pennsylvania, you come to Dominic’s party,” said Mr. Rendell.

The room throbbed with lawmakers, aides and lobbyists from all corners of the commonwealth — the kind of crowd that uses the term “commonwealth.”

“Even if you just buy a train ticket to Penn Station and stand in the Waldorf lobby you’ll meet everyone,” said Brian D. Gralnick, a director of the Jewish Federation of Greater Philadelphia.

His group was holding a dessert reception on Saturday night. There were also receptions paid for by the Marcellus Shale Coalition, the International Brotherhood of Electrical Workers and the Consol Energy Corporation, which had invited “Captains of Industry,” modern-day versions of those Fricks and Carnegies.

Most were invitation-only, and a reporter who indiscreetly pulled out a notepad was asked to leave more than one, including a fund-raiser for Mr. Toomey at a private residence on East 63rd Street.

At a gathering in the Louis XVI Suite of the Waldorf to honor the Republican leader of the State House, Mike Turzai, a fellow lawmaker in a Santa Claus tie balanced a Scotch and a plate of shrimp in one hand while a lobbyist described a bill he had drafted. “We’ll be sure to bury it,” chuckled the State House member, throwing his shrimp-free arm around the lobbyist’s shoulders.