Host of the event is her uncle, Sen. Edward M. Kennedy of Massachusetts, one of the most prominent members of Congress. The price of admission is $1,000 per person, with an expected take of about $100,000. The news media are not invited.
It is among the first overt displays of Townsend's family ties in the three weeks since the eldest daughter of Robert F. Kennedy formally announced her bid for governor of Maryland.
If history is a guide, it won't be the last.
"You are going to be overtaken by Kennedys and friends of Kennedys," said Darrell M. West, a Brown University political science professor and author of a biography of Rep. Patrick J. Kennedy of Rhode Island.
"There is a definite style to how the Kennedys go about campaigning," West said. "They take full advantage of their money and celebrity status. You will see prominent sports figures and Hollywood stars coming to fund-raisers. It will be a personality-driven campaign."
While Townsend embraces her birth name and appreciates its value, she and her aides deny it will dominate or define her campaign. Since launching her campaign, she has visited all but two of Maryland's 23 counties, talking mostly of state and local issues such as highway construction and funding for volunteer firefighters.
She scoffs at the notion that Uncle Ted, her famous cousins or her father's associates will swoop into Maryland and take control of the race. "Traditionally, families help somebody who runs. My family has always been very helpful," Townsend said. "But what people in Maryland want to know is what I can do about improving our kids' education, about reducing crime and about continuing our strong job growth. That's what the focus of this campaign will be."
Her campaign staff, said communications director Michael Morrill, consists of workers who have longtime commitments to Maryland. "Most of us have never worked for anyone else in her family," he said. "This is a very Maryland-based, Maryland-focused campaign, being run by and [with a] strategy developed by Marylanders."
West said he has heard lines like that before. "The Kennedys up here also play down the existence of a Kennedy machine, and they disavow that they are going to use appeals based on celebrity politics," he said. "But they still use it. Every Kennedy campaign I've ever seen uses it."
"The more reporters are asking them questions about Caroline Kennedy, the less they are asking about Medicare," West said.
Former Rep. Helen Delich Bentley experienced the Kennedy style firsthand in 1986, when Townsend ran for Congress in Baltimore County.
"Kathleen's brothers and sisters were there, and some of the cousins," Bentley said. "They would come down on street corners and try to push our people away. And we would push them away. We had a lot of fun."
Bentley won, but Townsend learned from the defeat. Never again would she run as Kathleen Townsend. In her two campaigns on a ticket with Parris N. Glendening, and again this year, her literature uses her maiden and married names.
James W. Hilty, a Temple University history professor who has written extensively on the Kennedys, said politicians in the family turn to the same themes, relying on their charm and on personal contact with voters.
"There tends to be a persistent pattern: When you engage one Kennedy in a political contest, you engage them all," Hilty said. "They have a wide network that extends back to the 1960s, many of whom are compelling figures in their own right, with their own contacts and resources."
Others contend that members of Townsend's generation of Kennedys have built their own bases of support that are distinct from Jack, Bobby and Ted.
"She has a lot of sources to draw upon that have no relation to her father's and uncle's and cousins' resources," said Theodore Sorenson, a former speechwriter for John F. Kennedy. "She has plenty of her own generation to draw from. She doesn't have to reach out to me."
To be sure, Townsend might turn to family members for advice and counsel. One brother, Robert F. Kennedy Jr., is a leading environmentalist, and another brother, Joseph P. Kennedy, the former Massachusetts congressman, is regarded as a masterful campaigner.
Ted Kennedy is a father figure to Townsend and her siblings, filling the void created by an assassin's bullet. Speculation abounds, however, that he is playing an even larger role.
Some wonder if he is working behind the scenes, pressuring Baltimore Mayor Martin O'Malley to stay out of a Democratic primary or encouraging Sens. Barbara A. Mikulski (who holds a subcommittee chair in Kennedy's Health, Education, Labor and Pensions Committee) and Paul S. Sarbanes to endorse his niece, as they did this week.
Steve Kearney, a spokesman for O'Malley, said he had no direct evidence of Kennedy family efforts.
"Do we know the motivation of everyone who speaks with the mayor? No," Kearney said. "But we haven't gotten any phone calls from Hyannis Port."
Aides to Mikulski and Sarbanes said they know of no communication between the senators and Kennedy, and Kennedy staffers say he is not actively involved in the day-to-day strategy or operations of the Townsend race.
"If she invites him in to campaign, I'm sure he'll be amenable to that," said Melody Miller, a senior aide to the senator. "He'll also be campaigning for Patrick Kennedy and for [Maryland congressional candidate] Mark Shriver."
Aside from tonight's fund-raiser, only a few clues of other family connections are apparent.
Townsend's campaign consultant is Robert M. Shrum, a former speechwriter for Robert Kennedy and press secretary to Ted Kennedy. He has worked regularly for family members, including providing counsel to Townsend's younger brother Max, who is considering a run for Congress in Massachusetts.
But Shrum, a leading Democratic consultant, has also worked in other Maryland races, including stints with Glendening, Mikulski and Sarbanes.
Her most recent campaign report says 38 percent of donations came from out of state. She has held fund-raising events at the family compound on Cape Cod, attended by celebrities such as Marvin Hamlisch.
That edge has scared off some challengers, but not Rep. Robert L. Ehrlich Jr., the Timonium Republican who says he is not sure whether he will face an organized family effort.
Ehrlich said he has received many e-mails urging him not to run that he traced to Democratic Capitol Hill staffers. But he said a celebrity brand of politics won't win votes; it will just solidify the support of those who would vote for Townsend anyway.
"It's a different state. It's a different era," Ehrlich said. "The president might help with swing voters. Caroline Kennedy doesn't win swing voters."
"I don't see this grand, orchestrated effort," said Michael S. Steele, the Maryland Republican Party chairman. "I see Hollywood coming east. I see Ted Kennedy showing up. But I've got President Bush. I've got Dick Cheney. Bring it on."