Even so, the killing of Dr. King created “a sense of disorder that was both unsettling and catalyzing” to Ms. Rodham, recalled Mr. Schechter, the political science professor and a mentor to her. Friends observed that she was less restrained and less deferential after Dr. King’s death.

At a panel discussion for a group of Wellesley alumni in mid-April, Mrs. Clinton bemoaned the “large gray mass” of uninvolved students. At another meeting, she argued with an economics professor who suggested that the strike take place on a weekend.

“I’ll give up my date Saturday night, Mr. Goldman, but I don’t think that’s the point,” Ms. Rodham told the professor, Marshall Goldman, according to the April 25, 1968, Wellesley News. “Individual consciences are fine but individual consciences have to be made manifest. Why do these attitudes have to be limited to two days?”

Ms. Rodham had traveled to New Hampshire several times that winter to volunteer for Mr. McCarthy, the Minnesota Democrat challenging President Lyndon B. Johnson for the Democratic nomination. Mr. McCarthy’s message — that the antiwar movement should operate within the system, not on the streets — appealed to Ms. Rodham. The candidate urged his supporters to be respectful, prompting the young activists to cut their hair, shave their beards and be “Clean for Gene.” That summer, Ms. Rodham took to the streets herself, albeit as a safe observer. While home in Park Ridge, she and a friend, Betsy Johnson, kept hearing about all the commotion downtown at the Democratic Convention. They drove Ms. Johnson’s parents’ station wagon into Chicago to view the spectacle.

“We thought we had seen all there was to see in our sheltered neighborhood,” recalled Betsy Johnson Eberling, another former Goldwater Girl. “It was a radicalizing experience for us, to some extent.”

Mrs. Clinton has said repeatedly how “shocked” she was at the brutality she witnessed — protesters throwing rocks, police officers beating protesters — but describes the bedlam with almost scholarly detachment. In her memoir, “Living History,” she recalls spending hours that summer arguing with a friend over the “meaning of revolution and whether our country would face one.” Even if there was a revolution, the two friends concluded, “we would never participate.”

Keeping a Toe in the G.O.P.

For all her leftward movement, Ms. Rodham still kept a toe in the Republican Party, working as an intern in Washington that summer. Mr. Schechter, who supervised the Wellesley internship program, sent her to work for the House Republican Conference, then headed by Mr. Laird, the Wisconsin congressman who would later become President Richard Nixon’s defense secretary. “My adviser said, ‘I’m still going to assign you to the Republicans because I want you to understand completely what your own transformation represents,” Mrs. Clinton recalled of Mr. Schechter.