In the United States, the Revolutionary Youth Movement (RYM) was the section of Students for a Democratic Society (SDS) that opposed the Worker Student Alliance of the Progressive Labor Party (PLP). Most of the national leadership of SDS joined the RYM in order to oppose PLP's party line and what they alleged to be its attempted takeover of the SDS leadership structure, particularly at the 1969 SDS convention in Chicago.
The theoretical basis of the Revolutionary Youth Movement was an understanding that most of the American population, including both students and the so-called "middle class," comprised, due to their relationship to the instruments of production, the working class; thus the organizational basis of the SDS, which had begun in the elite colleges and had been extended to public institutions as the organization grew, could be extended to youth as a whole, including students, those serving in the military, and the unemployed. Students could be viewed as workers gaining skills prior to employment. This contrasted to the Progressive Labor Party view which saw students and workers as being in separate categories which could ally, but should not jointly organize.
Politically, the RYM took issue with what they alleged was PLP's opposition to the right of self-determination for oppressed nations and ethnic groups. The RYM also criticized PLP's attacks on the Vietnamese National Liberation Front, whom PLP had accused of "selling out" to the U.S. during the Paris Peace Talks, as well as other criticisms. But most of all, the RYM opposed what it considered to be PLP's unfounded attacks on the Black Panther Party.
In the 1969 fragmentation of SDS, RYM departed the convention hall and declared itself the "real SDS" in a new space across the street.
In splitting the SDS, the RYM itself also split. One section of the RYM (referred to as RYM I), containing most of the SDS leadership including Bernardine Dohrn, David Gilbert and Mark Rudd, became Weathermen. Weatherman briefly retained control of the SDS National Office and membership lists before dissolving SDS and closing its headquarters in 1970, in favor of pursuing underground activities that it believed would help to spark revolution in the short term.