The Bull Moose (or Progressive) Party was the source of many of the big-government, intrusivist woes we are faced with today. TR was a great guy, but much more liberal than many realize.
You can look farther back for the root problem. The socialist revolutions in Europe of 1848 sent many marxists overseas to the USA as political outcasts. Many found homes in marxist publishing, farm-labor parties, academia, and Lincoln's new Republican party. Combined with TR's overweaning sense of noblesse oblige it was inevitable that a movement would arise to manage the people like a crop, for their own good.