This paper explores the brief administration of Sun Yat-sen, the first president of China, and why he failed to maintain power. I argue that during the provisional presidency, Sun tried to lay the groundwork for a modern constitutional republic centered around the “Three People’s Principles,” but he failed due to the broader political uncertainty brought by Yuan’s presence. When Yuan took power, Sun initially supported his administration, but soon he became frustrated with Yuan’s increasingly autocratic decisions. Sun’s political involvement, then, did not cease with the end of his presidential term; instead, he was politically active and even belligerently idealistic until Yuan forced him into exile in 1913. After telling the story of Sun's presidency using both his own writings and scholarship analyzing his relationship with Yuan Shikai, I conclude that Sun's republican idealism blinded him to the threat of authoritarianism that Yuan posed.