Call it a marriage made in Democratic heaven.

In a match that joined two of the country's leading political families, Kerry Kennedy, the daughter of Ethel Kennedy and the late Robert F. Kennedy, and Andrew Cuomo, the eldest son and chief political adviser of New York Gov. Mario M. Cuomo, were married yesterday afternoon at St. Matthew's Cathedral.

The bride, 30, and the bridegroom, 32, were married in an elaborate Roman Catholic wedding Mass, with readings by Gov. Cuomo, Rep. Joseph P. Kennedy III (D-Mass.) and Kathleen Kennedy Townsend. Kennedy and Townsend are the bride's brother and sister. More than 300 guests and a wedding party of 41 bridesmaids, ushers and flower girls and boys watched as Kennedy walked up the aisle alone to join Cuomo at the altar.

"They were very joyful, happy, smiling," said the Rev. Gerard C. Creedon, a longtime Kennedy family friend who performed the ceremony. "Kerry greeted everyone on the way up -- the congregation appauded as she came up the aisle."

The guest list, like most of the details of the ceremony, remained secret, but the wedding brought out the Kennedy clan, including Jacqueline Kennedy Onassis, Caroline Kennedy Schlossberg, John F. Kennedy Jr., Sen. Edward M. Kennedy (D-Mass.) and Maria Shriver (without husband Arnold Schwarzenegger). A planeload of Cuomo relatives, friends and political associates joined the governor. They included New York Mayor David N. Dinkins and Newsday columnist Jimmy Breslin.

The couple emerged from the church, site of both the funeral Mass for President John F. Kennedy and the 20th anniversary memorial service two years ago for Robert F. Kennedy, about 2:15 p.m. The newlyweds smiled but did not kiss for the 500 sightseers and paparazzi who lined the sidewalk across from the church in the 90-degree heat. The bridesmaids and groomsmen stood on the steps and tossed tissue hearts at the couple, who then left for the reception at Hickory Hill, the McLean estate of Ethel Kennedy.

"Magnificent," Sen. Kennedy saidof the service. "Perfect."

Kerry Kennedy wore an off-the-rack gown designed by Scaasi Bride. The dress of white silk satin ornamented with crystals, silver bugle beads and hearts of pearl had a basque bodice, a sweetheart neckline, puff sleeves, a voluminous skirt and a cathedral train. The bridegroom, his best man, 19-year-old brother, Christopher, the ushers and a number of the Kennedys wore morning suits.

The bride's younger sister, Rory, 21, and friend Mary Richardson, 30, were her maids of honor. Sisters Courtney Kennedy and Townsend were among the 13 bridesmaids, who wore white silk satin jackets with white floor-length chiffon skirts.

The mother of the bride wore a pale pink re-embroidered lace dress and the mother of the bridegroom, Matilda Cuomo, wore a champagne-colored re-embroidered dress.

Maureen Flynn, a 30-year-old map researcher at National Geograhic, arrived at 11:30 a.m. with camera for a prime spot across the street from the cathedral.

"I want to see everybody. I'm a Kennedy fanatic," said Flynn. "I've grown up with their books and pictures of them. They're beautiful."

Flynn even persuaded a tourist to stay for the ceremony. "You can always go to the National Archives," she told her. "You can't always see the Kennedys."

While family and friends remained characteristically close-lipped about the couple, who announced their engagement in February, the word "dynasty" has been tossed around so much one half expected to see Joan Collins jump out of one of the 25 limousines triple-parked on Rhode Island Avenue NW.

The union is reminiscent of such second-generation political alliances as David Eisenhower and Julie Nixon (1968), Sharon Percy and Jay Rockefeller (1967) and Lynda Bird Johnson and Chuck Robb (1967).

"It's got awful good bloodlines," said Frank Mankiewicz, Robert F. Kennedy's former press secretary. "It's like they say in baseball -- it's one of those trades that helps both clubs."

Kerry Kennedy is executive director of the Robert F. Kennedy Center for Human Rights. Andrew Cuomo, who was his father's campaign manager at age 24, now heads HELP, a Manhattan foundation to help the homeless.

Following a honeymoon in the Caribbean, the couple will settle in Queens, N.Y., where there is speculation Cuomo will run for Congress.