As her speech unfolded, it became increasingly critical of the administration of the man who defeated her in November, without ever naming him.
She drew parallels between the year she graduated and the current year, noting that the president who was elected back then had ultimately been impeached for obstruction of justice. And she lacerated the atmosphere of "alternative facts," warning that this can lead to the beginning of the end of a free society.
She spoke under an enormous white tent as a persistent drizzle coated the lush campus, where the top of Galen Stone Tower and its 32-bell carillon poked above the trees.
It is hard to imagine a more fitting place than Wellesley for Mrs. Clinton, 69, to reflect on her life's trajectory. The college's commencement has served as her platform twice before, at major turning points in her life.
It was here in 1969 that a 21-year-old Hillary Rodham, president of her class with a freshly minted degree in political science, was chosen by her classmates as the first student to deliver a speech at commencement.
And in 1992, during her husband's first campaign for president - when she raised hackles for sounding more like a running mate with opinions and ambitions than an acquiescent wife - she spoke again at the Wellesley commencement. It was a politically safe speech, in which she mused on balancing family, work and public service.
But in 1969, she was more daring. She caused a stir by criticizing, however obliquely, the commencement speaker, a United States senator. Her comments landed her in Life magazine as a voice of her generation and catapulted her onto the public stage.
Today, those remarks about the commencement speaker, Senator Edward Brooke, Republican of Massachusetts, seem quaint. Yet 48 years after her graduation, her words about the idealism of a student starting college and determined to change the world seem more significant.
"We arrived not yet knowing what was not possible," she said in 1969. "Consequently, we expected a lot."
Now, of course, she knows what is not possible.
Mrs. Clinton has kept a low profile since her humiliating and unexpected loss for president in November to Donald J. Trump. Her re-emergence onto the public stage has been slow and methodical. She delivered a political speech in March in San Francisco, in which she criticized the administration's plans for overhauling health care and deplored the persistent indignities faced by women and minority women in particular.
In May, she announced that she would start a political action organization called Onward Together that would funnel money to groups that resist Mr. Trump's policies.
In an interview with CNN at the time, she sought to reassure her supporters that she was no longer hibernating, declaring: "I'm now back to being an activist citizen and part of the resistance."