New York and Washington power brokers gathered last night at the Four Seasons for a Newsweek party. It was a social feat that only host Lally Weymouth, daughter of Katharine Graham and long-time New Yorker, could pull

The R Party at Roseland Sunday night, hosted by Jenna and Barbara Bush, drew hundreds of 20- and 30-somethings.

Dustin Lane, a delegate from Washington, exchanged numbers with Erin Carrington and Shakera Jones, both convention volunteers.

On the dance floor were Nicole Wright of New York and Walter Michel of Mississippi, who met that night. Iowa dele off.

Ms. Weymouth greeted the likes of real estate scion Jerry Speyer, Speaker Dennis Hastert, and CBS chief Leslie Moonves.

City Hall took notice: Mayor Bloomberg, William Cunningham, and Daniel Doctoroff were all present. Mr. Doctoroff talked with the president of the Jets, Jay Cross, while Jets owner Woody Johnson greeted Roland Betts and Brad Freeman. Other conversation partners: Georgette Mosbacher, Barbara Walters, and Ray Kelly; Dana Milbank of the Washington Post and Jacob Weisberg of Slate; Tina Brown and the editor of the New Republic, Peter Beinart; Herbert London, Midge Decter, and Norman Podhoretz (holding a copy of A.S. Byatt’s “Babel Tower”); actor and convention speaker Ron Silver and his daughter Alexandra; Henry Stern and Ray Price, and Donald Marron, Pepe Fanjul, and William Rudin.

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Isaiah McGee sang along to Sinatra’s “New York, New York.” But it wasn’t all young things in pearls and khakis. Granddads and children also partied with varying degrees of enthusiasm. At 11:30 p.m., older guests were seen snoozing on the sidelines. Nearby, 8-year-old Francis Carlota of Memphis, Tenn., wore a wide grin. “This party is awesome,” said Francis, who came with his parents (his dad is the chairman of the National Filipino American Republican Council). As the first daughters only appeared briefly, high-profile disc jockey Tom Finn – whose next big gig is Fashion Rocks on September 8 – kept the party grooving. He introduced bands, including Mission 19, Jill Phillips, and Dexter Freebish. Packed when it started, the numbers quickly dwindled once guests realized that they had to pay for drinks and food – hamburgers went for $6, French fries for $3.