Clinton, who has long been a devotee of Soul Cycle, welcomed riders as they entered the studio, many of whom she was familiar with. She took photos and spoke to the packed class for a few minutes before the ride, taking several questions.
One woman asked her who she would pick "if she had to pick a Republican opponent," an attendee told CNN.
Clinton "talked about how she thinks that Jeb Bush is ... the only voice on the other side that is demonstrating strong American values," the source said.
The former first daughter "mentioned how this is her first election as a mother and how important women's rights are to her and the campaign," the source added. Clinton announced last month
that she and husband Marc Mezvinsky are expecting their second child this summer.
It was obvious Clinton wasn't going to be riding along with the group, the attendee said, because she was dressed in normal clothes, not the Soul Cycle uniform of spandex pants and tops. Clinton cited no specific reason for why she wasn't going to ride.
Chelsea Clinton repeatedly touted her mother's discipline and consistency, and acknowledged the challenge her mother, Hillary Clinton, is facing from Vermont Sen. Bernie Sanders.
The fundraiser was originally billed as a $2,700-a-head event, but with about 60 seats to fill, some attendees were able to snag tickets at the last minute for $50. Riders pedaled stationary bikes to the beat of tunes like Guns N' Roses' "Sweet Child O' Mine" and "Fight Song" by Rachel Platten, the latter a part of Hillary Clinton's campaign play list.
The instructor, Laurie -- who, like all Soul Cycle teachers, goes only by her first name in class -- said she had instructed the presidential candidate through a spin session and continually made comments throughout the class in support of Clinton. Her mantra, listed in her online bio, is, "Happiness isn't created by accident, it's created by design," a motto that parallels the approach Hillary Clinton has taken in her carefully orchestrated 2016 campaign.