WASHINGTON — Under the glittering lights of a ballroom in a hotel whose name is synonymous with political scandal, they gathered for a reunion.

They arrived at the Watergate in summer suits and cocktail dresses, pinning on name tags with red, blue and white stripes to help nudge 45-year-old memories of the months spent investigating an episode that one White House official dismissed as a third-rate burglary — but that stretched to the Oval Office and brought down President Richard M. Nixon.

“You haven’t changed a bit,” said Elisabeth DeMarse, as she stood up to embrace a man outside the ballroom, kissing the top of his clasped hands. “I am so excited to see you.”

It was a historic reunion, the guests told one another, held this weekend to mark the 45th anniversary of the 1972 Watergate break-in. It was the largest gathering in recent memory of the remaining members and staff of the Senate Select Committee on Presidential Campaign Activities — known in Washington shorthand as the Watergate Committee — who came together to listen to a panel of the highest-ranking committee staff members discuss the investigation and share memories of their work.