In the 1880s and 1890s, populists in the South, like Tom Watson, generally believed in allowing African Americans to vote. They did this not because they believed in racial equality, but because they believed that African Americans could be their political allies.
The populists in the South in this time were largely farmers. The farmers felt that they were being abused by the banks and the railroads. They needed loans every year to tide them over until the harvest. They felt that the banks exploited them because of this need. They needed to use the railroads to bring their crops to market. Most areas had only one rail line and the farmers felt that railroads exploited them because the railroads had monopoly power. The populists knew that most African Americans at this time were engaged in agriculture. They also knew that black farmers shared in the same problems that white farmers faced. For this reason, they wanted African Americans to be able to vote. They felt that the African Americans were their natural allies. They put their economic interests ahead of their racial prejudices and supported black voting.