Ken Duberstein, uber-lobbyist and former chief of staff for President Ronald Reagan, swept into a second-floor room at the Jefferson Hotel, resplendent in monogrammed cuffs and Hermes tie, looking for the perfect suit.

The search for this exquisite instrument began discreetly off an elevator reached through the hotel's restaurant. Upstairs, in less than a half-hour, Duberstein ordered a hand-cut, handmade custom suit from Simon Cundey, managing director of Henry Poole & Co., one of the founding tailors on London's Savile Row.

Cundey tended to 15 customers over two days last month, almost all based on references or word of mouth. Most were lawyers, foreign diplomats and other accomplished men in middle age who recently slipped into the hotel for timed appointments of no more than 40 minutes, like a low-key, high-powered lunch at a private club.

If Washington's uniform is the suit, the ultimate expression of power is the hand-cut, handsewn, custom suit. Among Washington aristocracy, few admit publicly to the extravagance. But they're flattered when peers notice a perfect fit, a smooth line, a good fabric, and they make recommendations confidently, like introducing a friend to a special fraternity.

It's a club whose members include World Bank President James D. Wolfensohn and Secretary of Commerce Donald L. Evans, former NASA administrator Daniel S. Goldin and Arthur Levitt Jr., former chairman of the U.S. Securities and Exchange Commission.

In the competitive world of custom tailoring, in which tailors charge $2,500 and more and get snippy about their competitors, the stereotype of the rumpled politician seems to have been folded up and stuffed in the back of a closet.

"In Washington, things have to be well-suited, literally and figuratively," said Duberstein, clad in a navy chalk-striped suit and a crisp blue shirt with white collar. "This gives you the elegance, the style, the conservative dress that speaks volumes about where you've been and what you're all about."

John B. Henry, entrepreneur and chief executive of an online marketplace for legal work, uses a Georgetown tailor who goes by one name, like Madonna or Cher. "Baytok's an artist, a sculptor. He's just using cloth as his medium," Henry said. "The suits just look better -- they just absolutely hang on you."

Washingtonians are quick to claim their sartorial conservatism. This isn't Wall Street. No Washingtonians made the final cut this year for Esquire magazine's best dressed men in the world (politicos who did make it included San Francisco Mayor Gavin Newsom and the just-reelected Afghanistan president and fashion plate, Hamid Karzai).

Politicians aren't the best source of personal style, said Esquire's fashion editor, Nick Sullivan. "I get the feeling that in the corridors of power, the image-mongers are saying, 'Don't wear that tie -- you'll get noticed,' " Sullivan said.

Yet ask around on the Hill, "Who's the best-dressed member of Congress?" and names quickly surface: David Dreier (R-Calif.) and Jim Ramstad (R-Minn.) in the House. John W. Warner (R-Va.) in the Senate, or perhaps Jon S. Corzine (D-N.J.). Two senators, Gordon Smith (R-Ore.) and Orrin G. Hatch (R-Utah), routinely make the best-dressed lists in Washingtonian magazine.

The week before Henry Poole & Co. was ensconced in the Jefferson Hotel, George Cleverley Bespoke Shoemakers booked a room, catering to customers willing to sit through two dozen measurements for a custom leather shoe.

Henry, the entrepreneur, was one of them, having heard about the London shoemaker from star chef Gerard Pangaud, the owner of Gerard's Place.

It was Ramstad who turned lobbyist Jeff Kimbell on to Baytok, whose suits start at $2,500. "I've got a couple of clients in Jim's district, and he always looks sharp," said Kimbell, who complimented Ramstad on one of his suits and said the congressman then recommended its maker.

Kimbell is sold on bespoke suits because they last. Others are hooked by the ease of shopping for a new suit after the initial fittings are done.

Bespoke comes from bespoken, and it means "to speak about your clothes," said Cundey, of Henry Poole & Co. It means a suit is hand-cut and handmade on the premises. A paper pattern is made for each individual. Machine stitching is kept to a minimum.

Made-to-measure suits, sewn by machine in a factory after a tailor takes a customer's measurements, don't travel well, Kimbell said. "I've tried Hong Kong-tailored suits. I gave up on that," Kimbell, 33, said. "I've sort of made the transition from the Brooks Brothers days of my twenties."

Over the years, Henry Poole & Co. has collected about 200 customers in Washington, Cundey said. Some come to the Jefferson to choose fabrics. Others meet him for trunk shows and fittings in New York twice a year. Henry Poole suits, worn by tastemakers from Napoleon Bonaparte to Winston Churchill, start at $3,600.

"The achievement is to feel like you're not wearing a suit," Cundey said. "We give you a small armhole so when you reach up, the collar doesn't rise. We balance you up. If you have big hips and are pear-shaped, we try to give you more of a shoulder, so you're more hour-glass shaped."

Joe Sauro has kept a tailoring shop downtown for 40 years, but he stopped making custom suits 16 years ago when it was no longer profitable for him.

"Financially, it's the best thing I ever did, going into the formalwear business," he said.

Photographs of Sauro's well-known clients decorate his shop. Among them are former presidents Richard M. Nixon, Reagan and George H.W. Bush, and President Bush. One recent photo shows Sauro in the White House private residence, measuring the current president before altering one of his suits.

"Men in my day didn't really pay much attention to what they wore," said Sauro, who still does alterations. "Now, they take better care of their bodies."

Ambassador Randall L. Tobias, appointed by President Bush to coordinate federal efforts to combat HIV/AIDS, was originally fitted by Henry Poole & Co. more than a decade ago and rarely has to try suits on because he stays in shape.

"If my suits start not fitting, then I know I'm gaining weight," said Tobias, a former chief executive of pharmaceutical giant Eli Lilly who ordered three suits in 15 minutes at the Jefferson Hotel.

"I've become very comfortable with the particular design of suit that I like to wear, and every suit is identical," said Tobias, whose gray suit was so well-cut the tools of his craft -- wallet, business cards, PDA -- were invisible. "When I open the jacket, there's a pocket for my BlackBerry and there's a pocket for my cell phone. It's just easier."

For others, custom tailoring is the only option.

"If you're like me and you're not totally normal, I need all the help I can get," said former White House counsel C. Boyden Gray, who goes to Baytok because, at 6 feet 6 inches, he cannot find off-the-rack suits that fit.

"There's nothing wrong with spending a little bit more on your clothes," Gray added. "They last a long time, and you can get another pair of trousers if you rip them."

Michael Retzer flies into Washington every other week from Greenville, Miss., to serve as treasurer for the Republican National Committee. On many visits, he can be found stopping in for a fitting with Georges de Paris, a 14th Street NW tailor who speaks five languages.

"It's an extravagance, but it's a good extravagance," Retzer said on a recent visit, standing next to thank-you notes de Paris has posted from President Bush and former President Bill Clinton. "It's always true that well-dressed men and women stand out in a crowd. . . . There are 536 elected officials here, all trying to get to the top of the heap."

Staff researcher Bobbye Pratt contributed to this report.

Simon Cundey of Henry Poole & Co. sets up shop temporarily at the District's Jefferson Hotel to provide custom suits to diplomats and other dignitaries. Simon Cundey of Henry Poole & Co. fits U.S. Ambassador Randall L. Tobias for a custom suit at the Jefferson Hotel.