Young activist: 1964–1968
At Reed College, Davis was overwhelmed, alienated by the hippy culture and struggling academically. He joined the Portland, Oregon chapter of CORE, which included the labor historian Jeremy Brecher, who at the time was one of few members of the nascent Students for a Democratic Society (SDS) in the Pacific Northwest. Living "drunk" in the dorm of a girlfriend for five weeks, Davis was expelled from Reed for intervisitation. Davis was eligible for the draft after his expulsion and passed the physical, but he was rejected after he insisted to the personnel at the induction center he belonged to several subversive organizations. After reading the Port Huron Statement, and at the recommendation of Brecher, Davis boarded a Greyhound bus to New York City to join the national office of SDS, arriving in November 1964. In 1964 and 1965, Davis worked in the national office of SDS, which was becoming overwhelmed by the growing number of chapters. The national council meetings gave the office the responsibility to organize two major demonstrations, an Anti-Apartheid sit-in and the first march on Washington in protest of the Vietnam War.
Davis was one of the chief coordinators behind the anti-Apartheid sit-in at Chase Manhattan Bank. In the aftermath of the Sharpeville massacre, Chase Manhattan had led a consortium of international banks that bailed out the Apartheid government of South Africa. The chief ally and tactical organizer to the sit-in was the New York chapter of the Student Nonviolent Coordinating Committee (SNCC), headed by Betita Martinez (then Elisabeth Sutherland), who Davis became acquainted with. Other supporters included exiled members of the African National Congress and young members of the Tanzanian mission to the United Nations. On the Friday afternoon of March 19, 1965, some 600 demonstrators marched on Chase Manhattan's offices, with 43 arrested, in what was SDS's first act of civil disobedience.
Davis returned to California in early 1965, arriving in the Bay Area during the transformation of the Free Speech Movement into the Vietnam Day Committee. His only subsistence for the next six months was money earned by selling literature sent to him by the SDS national office. The demand for radical literature by students in the Bay Area was enough that Davis could afford to rent a derelict house with no electricity. While couch surfing in the homes of academics, he became aware of Herbert Marcuse, who was lauded by the organizers of the Free Speech Movement. Davis had struggled to understand any of Marcuse's One-Dimensional Man, but opted to write a letter to the respected academic about the accomplishments and motives of SDS. Marcuse responded, but was critical, suggesting that SDS was only serving to advance Lyndon B. Johnson's War on Poverty, and that the organization should seek a more oppositional approach. While in Oakland, Davis burned his draft card in protest of Johnson's intervention in the Dominican Republic.
In June 1965, after burning his draft card, Davis was sent by the SDS national committee to Los Angeles, where he was ordered to assist in organizing protestors against the construction of the 210 freeway through a historically Black neighborhood in Pasadena. Davis and other SDS members also organized weekly meetings to spread awareness about the draft on local campuses. Working in South Los Angeles, he befriended Levi Kingston, a former jazz bassist and radicalized sailor from the Merchant Marine. Kingston previously ran a coffeehouse, Pogo's Swamp, which served as a local hub for beatniks and radical students at Los Angeles City College, including the future founder of US Organization, Ron Everett. Kingston connected Davis with local activists in South Central, and the two worked together organizing draft resistance and doing draft counseling. On August 16, 1965, during the Watts uprising, Kingston was shot at by a vigilante from the roof of a fraternity house of USC. Davis was at Kingston's side during the shooting, and noted that Kingston, who was Black, was the only one targeted. Kingston later organized a Black draft resistance organization, the Freedom Draft Movement, and remained close friends with Davis for the rest of his life. Davis viewed Kingston as his "big brother" and one of the major figures in his life, and would dedicate his last book, Set the Night on Fire, to Kingston, who died shortly before it was published.
In 1966, 19-year-old Davis, characterized as a "draft card-burning SDS leader," debated actor Kirk Douglas on Melvin Belli's talk show. The section of an article in the Los Angeles Times on the debate, titled "Outtalked by 19-Year-Old," described Davis "...to have much less trouble stating his case then either Belli or Douglas," while Douglas "...was having some difficulty being articulate on his own behalf." In his recollection on the appearance, Davis, the first to be on, was confronted by Douglas as he was leaving the studio. Douglas allegedly called him a "commie dupe." Davis responded by telling Douglas that he admired his appearance in Paths of Glory, but questioned why the actor would star in an anti-war film while serving as a goodwill ambassador for the Johnson administration in Southeast Asia. According to Davis, Douglas was "speechless."
As the Southern California regional organizer in 1966, Davis organized protests in support of the anti-war and civil rights movement. The first, in February, was a rally in solidarity with Julian Bond and the peace demonstrations in the South, meant to bring closer ties between the peace and civil rights movements. In May, Davis helped organize a protest against the manufacture of napalm used in the Vietnam War by Dow Chemical, with SDS picketing the Dow Chemical plant in Torrance in coordination with other national protests originating from the Stanford Committee for Peace in Viet Nam. The Torrance picket was countered by demonstrators from the Victory in Vietnam Association, headed by local chapter leader Dana Rohrabacher. Davis also frequently spoke on behalf of SDS in public debates and conferences on world affairs and social revolutions.
In 1967, Davis briefly left Los Angeles to organize for SDS in Texas, and lived in Austin. While in Texas, Davis sought out the populist news editor Archer Fullingham. At the time, Davis was still wary of Marxism and the number of his friends who were becoming Marxists, and instead was interested in the idea of reviving the Populist Party. He approached Fullingham at his residence in Kountze, and proposed the idea to the editor, suggesting that Fullingham could be the leader of the party. According to Davis, Fullingham rebuked him, calling him "...one of the dumbest piss-ants I've ever met," and suggested Davis "figure out this stuff for yourself."
In late 1967 and 1968, Davis returned to Los Angeles and joined the Southern California District of the Communist Party, headed by Dorothy Healey, in solidarity with their stand against the Soviet invasion of Czechoslovakia. He left SDS after the 1969 "Days of Rage," and looked back on the achievements of the movement with ambivalence.
His education was punctuated by stints as a meat cutter, truck driver, and a Congress of Racial Equality (CORE) and Students for a Democratic Society (SDS) activist. At 28, Davis returned to college, studying economics and history at the University of California, Los Angeles on a union scholarship. Davis earned his BA and MA degrees, but did not complete the PhD program in history.