The major characteristic that all of these presidents shared is that they were interested in having the government work to reform the United States. They all felt that business had too much power and that it should be reined in.
Beyond that, there were differences between them. Roosevelt was by far the most forceful personality whereas Taft was happier as a judge and Wilson was more of a professorial type. Wilson was much more idealistic in his foreign policies than was Roosevelt, who believed very much in the idea of “big stick diplomacy” and of having the United States get its way by whatever means were necessary. These were important differences, but they should not obscure the fact that all of these men were basically progressive, which sets them apart from their predecessors of the late 1800s and their successors of the 1920s.