“The City of Conversation” at Arena Stage is set in the lost world of Georgetown dinner parties and focuses on a character based on the legendary hostesses of the past. (C. Stanley Photography)

Remember when every problem in Washington could be solved over a glass of brandy? When partisan politics were set aside by reasonable people for the common good?

Okay, it never happened quite that way. But nostalgia is a stubborn thing, which explains the myth of the Georgetown dinner party. The latest homage to that world is “The City of Conversation,” a new play at Arena Stage.

Twenty years ago, Sidney Blumenthal wrote “The Ruins of Georgetown,” a New Yorker essay lamenting the end of Washington’s liberal elite and the influential women who ruled there. Playwright Anthony Giardina remembered the essay when he was writing about modern American politics and used that period as the setting for his play.

The political drama centers on Hester Ferris, a Georgetown hostess inspired by the likes of Katharine Graham, Evangeline Bruce, Lorraine Cooper, Pamela Harriman, Susan Mary Alsop and Sally Quinn. The play opens in 1979 as Hester is about to host a “hugely important” dinner to help Ted Kennedy win a key Senate vote.

We invited three Washington grandes dames — Republican doyenne Buffy Cafritz, who married into one of the city’s leading families; jeweler Ann Hand, who came to the capital with Lyndon Johnson in the late 1950s; and Lea Berman, White House social secretary in the George W. Bush administration — to see the production and point out what it gets right and what it gets wrong. All three knew some or all of the real hostesses of the past and have spent decades navigating Washington’s social scene.

Since the play is a work of fiction, we gave Giardina dramatic license to let his characters say or do anything in private. We focused on what happens in public. How realistic is Hester as a Georgetown hostess? Does the play accurately capture the texture and tone of the times? And what’s with that black cocktail dress?

Spoiler alert: Though we don’t give away the play’s big twist, we do discuss a few plot points.

Reality check 1: Hester is an outspoken, unapologetic liberal . Believable?

Frustrated by Jimmy “President Seatwarmer” Carter, eager for Ted Kennedy to run for president, disdainful of conservatives, Hester is deeply invested in the idea of a second Camelot. “We’re an arm of government, you might say,” she explains. “Georgetown. Dinners in Georgetown. Or we were. And will be again.”

This legend is based on a short window of glory, when intellectual liberals settled in the brick townhouses of the prestigious Washington neighborhood after World War II and became a power elite after John F. Kennedy was elected. The wives of the wealthy and powerful entertained lavishly and often, inviting Democrats and Republicans alike to their homes. There were battles, but not wars, and an expectation of civility.

These hostesses, many bright and educated, had opinions but didn’t express them with more than a raised eyebrow or a disapproving look. Hester, on the other hand, is strident and openly contemptuous — something unrealistic for a socialite of her time.

“You can’t behave like that, which is why the whole system broke down,” says Berman. As long as Ronald Reagan and House Speaker Tip O’Neill were friends, people made an effort to treat each other well. “When that example went away and views hardened, everything changed.” Berman remembers a private dinner party that she and her husband attended as the only Republicans in 1987, near the end of the Reagan administration. “We were attacked for two hours straight,” she says. “We came home that night and said, ‘I’m never going back there again.’ ”

Playwright Giardina says he researched the women of Georgetown for 14 years, diving into biographies and political histories for inspiration. But Hester is his own creation: “I wasn’t basing Hester on anyone in particular,” he says. “She has the freedom, in my world, to do anything she wants.”

Reality check 2: Hester’s lover is the married senior senator from Virginia.

Sen. Chandler Harris is married — perhaps separated, but not divorced — and has been involved in a long-standing relationship with Hester, also apparently divorced. Hester tells her son that she and the senator have been able to keep their affair out of the newspapers because they don’t show up at parties covered by The Washington Post.

She has invited Sen. George Mallonee and his wife, conservatives from Kentucky, to dinner in an attempt to persuade Mallonee to switch his vote on one of Ted Kennedy’s pet projects. If Harris can secure Mallonee’s vote, Hester explains, he has a shot at a Cabinet position or even the vice presidency if Kennedy becomes president.

Ridiculous on several fronts, say all three women. In 1979, any married senator (especially from the South) having an open affair would never be able to keep it a secret. He wouldn’t invite a conservative colleague to dine with his mistress. And he’d never have a serious shot at a Cabinet post, much less the vice presidency, without his wife at his side. “He’d be in the paper and people would be talking about” the affair, says Hand.

“No way would that have happened,” says Cafritz. Formidable Post reporter “Maxine Cheshire would have had a ball with that one.”

Michael Simpson as Colin Ferris and Margaret Colin as Hester. When her son and his girlfriend show up on the day of her important dinner, Hester invites them to join the party. Would a real Georgetown hostess have done that? (C. Stanley Photography)

Reality check 3: Hester invites her son and his girlfriend to join the dinner party.

Hester’s son and his girlfriend, both students at the London School of Economics, arrive home unexpectedly on the day she is hosting the dinner. Hester has never met the young woman but insists that both Colin and Anna join the party. “This is important,” she tells him. “You have to promise to behave.”

Unrealistic, says our panel of experts. Although the typical Georgetown dinner was larger, about 12 to 16 people, a good hostess would have very carefully assembled a guest list for such an important evening. She might have included her son but would have been unlikely to risk throwing his unknown girlfriend into the mix.

(Not to mention: The London School of Economics was known for its far-left leanings during the 1960s and ’70s; Colin and Anna, both “stars” at the school, are both Reagan conservatives in the play.)

Another miss: Hester insists that Anna wear one of her own dresses for the evening, a short, revealing black cocktail dress that Hester wore at Richard Nixon’s second inaugural. But inaugural balls were formal affairs, and almost every woman would have worn a long gown, especially a middle-aged socialite like Hester. Of course, an outspoken liberal probably would never have been invited to or attended a Nixon celebration.

Reality check 4: The men retire to the living room for brandy and cigars.

After dinner, the two senators retire to the living room without the women.

Totally true, says Cafritz: “I did it in my own home. That was the custom.”

The women would typically go to another room for tea; at Cafritz’s house, they went upstairs to put on lipstick and gossip for 20 minutes or so. “We didn’t think anything about it,” says Hand.

That tradition was gone by the 1980s, a victim of the women’s movement and a new generation who thought it was sexist and unfair — the ambitious Anna refuses to leave the men after dinner, hoping to land a job with the conservative senator.

And the set, with lots of well-worn chairs and traditional furniture, is spot on. The furnishings in Georgetown drawing rooms were never too modern or too new. Nothing screamed, “A rich person lives here!” Especially if one did.

Reality check 5: Hester is patronizing and rude to her guests.

She insults the senator’s wife when discussing the movie “Apocalypse Now”: “You’re aware it’s based on Joseph Conrad’s ‘Heart of Darkness,’ ” she explains grandly. She gets into a public battle with Anna and belittles her son.

Realistic? A little. “Among the political establishment in Washington, there is a real condescension,” says Berman. “People judge. I’ve certainly heard people say snippy things; passive-aggressive is perhaps a better way to describe it.” But all the women say that they would be stunned by the nastiness Hester directs at Anna.

The great Georgetown hostesses were accomplished manipulators, more likely to pour on the charm than to chastise. The master at this was Pamela Harriman, who always had an agenda and always enlisted powerful men to help. Cafritz’s late husband, Bill, was her dinner partner a few times.

“She would put her hand on his knee and never take her eyes off him,” explains Cafritz. “He would get in the car and say, ‘She’s terrific!’ ”

(Why couldn’t that be in the play?)

But there’s real life and there’s drama. Overall, all three women liked the production — the development of the characters, their emotional journey and the relatively balanced argument for classic liberalism and conservatism.

“These were the two extremes: Hester is on the left and Anna on the right,” says Cafritz. “There are no common-ground moderates.”

Once again, art imitates life.