Divided and thwarted in the 1920's, the various components of progressivism came tentatively together in 1932.
The other important reason was that the members of scientific party who were inclined to scientism were for the evolution viewpoint of progressivism.
More than any other sport, the NBA allows for both individual flash-and-dazzle theatrics and solid fundamentals-progressivism and conservatism, all in a single possession.