"As the 1948 election approached, Norman Thomas was reluctant to once more take up his party's standard....Thomas appealed to A. Philip Randolph to accept the quadrennial honor, but Randolph's first loyalty was to his union and the struggle for civil rights..." https://books.google.com/books?id=MnflBgAAQBAJ&pg=PA436
Suppose Randolph was willing to accept the Socialist presidential nomination. Considering that Truman won Ohio by only 7,107 votes, California by 17,865, and Illinois by 33,612 https://en.wikipedia.org/wiki/United_States_presidential_election,_1948 could Randolph have diverted enough African American votes from Truman to make a difference? (One problem: the Socialists were apparently not even on the ballot in Ohio. But California and Illinois would be enough to deny Truman an Electoral College majority...) Remember that in nominating Randolph, the Socialists would have gone further than the Communists had up to that time--they had only nominated an African American (James W. Ford https://en.wikipedia.org/wiki/James_W._Ford in 1932, 1936, and 1940) for *vice* president. And whereas Ford had no special standing in the African American community beyond Communists, Randolph was a very well-known civil rights and labor leader. https://en.wikipedia.org/wiki/A._Philip_Randolph
Suppose Randolph was willing to accept the Socialist presidential nomination. Considering that Truman won Ohio by only 7,107 votes, California by 17,865, and Illinois by 33,612 https://en.wikipedia.org/wiki/United_States_presidential_election,_1948 could Randolph have diverted enough African American votes from Truman to make a difference? (One problem: the Socialists were apparently not even on the ballot in Ohio. But California and Illinois would be enough to deny Truman an Electoral College majority...) Remember that in nominating Randolph, the Socialists would have gone further than the Communists had up to that time--they had only nominated an African American (James W. Ford https://en.wikipedia.org/wiki/James_W._Ford in 1932, 1936, and 1940) for *vice* president. And whereas Ford had no special standing in the African American community beyond Communists, Randolph was a very well-known civil rights and labor leader. https://en.wikipedia.org/wiki/A._Philip_Randolph