President Theodore Roosevelt appointed William Howard Taft as his war secretary. He declined to run for reelection and supported Taft for the presidency. Taft won the election, against the Democrat William Jennings Bryan.
Progressives who had supported Theodore Roosevelt for the presidency did the same for Taft. They believed that he would continue supporting the progressive agenda supported by his predecessor. However, they were disappointed when during his presidency they noticed he was a conservative.
Taft as president failed to appoint reformers from the progressive side of the republicans to his cabinet. He was uncooperative of the progressive agenda and supported legislation deemed retrogressive by the progressives. This was observed after Taft supported the Payne-Aldrich Tariff, which did not revise tariff rates to the level expected by progressives. In this regard, Taft was seen to be supporting big business against the small man, an issue of discontent among the progressives.
His relationship with Roosevelt soured when he relieved Gifford Pinchot from his duties as head of the Bureau of Forestry. Pinchot was a friend of Roosevelt and an ardent progressive reformer. In summary, Taft offended the progressives and his predecessor because of his alignment and support of the conservative agenda.