In the following years, the African National Congress (ANC) leadership evolved to be more inclined to action than passive deputation, but very little was achieved during the 1920s and 1930s. The ANC continued to criticise the government and called for changes, participated in the 1919 anti-pass campaign, and resisted the Hertzog Bills, which called for ‘comprehensive segregation’. The effects of their protests were however, not far reaching, and their support base remained middle-class.
It was in fact the trade unions that were more effective with regards to the masses at this time. In 1919 the Industrial Commercial Workers Union (ICU), founded by Clemens Kadalie, with support from the dockworkers in Cape Town, became a mass movement most active in the 1920s. For much of the 1920s the ANC was considered moribund, with the ICU dominating the political landscape in both urban and rural areas of South Africa. The late 1920s saw internal conflict between moderates and those that supported the more radical ideas of Marcus Garvey. Lack of political success eventually led to those with more radical ideas coming to the fore, Josiah Gumede being one of the most prominent from this group.
In 1927 Gumede became president of the ANC, and spent some time in the Soviet Union. The ANC began to work together with the Communist Party of South Africa (CPSA) on some of their campaigns, until Gumede lost the presidency in 1930 and the ANC officially rejected communism. Seme took over as president, and tried to bring the ANC back to its more moderate path. Yet, the 1930s saw the rise to prominence of the SACP, particularly in some Black townships as the ANC experienced a marked decline.
However, the proceeding years were filled with excessive internal conflict, which left the ANC quite ineffective against the government. This was also due to the fact that the government was taking action against resistance organisations, and that the ANC lacked the support of the masses. There was even talk in the mid-1930s of disbanding the ANC and starting a new organisation that did not have the same problems with leadership conflict. However, the Jubilee Celebration in 1937 demonstrated the fact that the ANC did in fact have a substantial support base.