 UCAPAWA was particularly strong among Mexican and Mexican American workers.In 1940, the "San Francisco News" called UCAPAWA the "fastest growing agricultural union in California", and attributed its success to its appeal to Mexican and Mexican American workers.The union was also supported by such outside organizations as the John Steinbeck Committee to Aid Agricultural Organization, the J. Lubin Society, the Spanish-speaking Peoples Congress, and on occasion, local clergy.