How and why do some social movements successfully transition into political parties? Within one year after the Sunflower Movement, Taiwan saw the formation of not one, but four new political parties. Amongst these four parties, two in particular, the New Power Party (NPP) and the Social Democratic Party (SDP), became the frontrunners of Taiwan’s new wave of movement parties, known colloquially as Third Force parties. One common explanation in political science for political party formation, particularly out of social movements, is that no existing political party was able to represent the movement’s political ideologies and stances. In other words, if an existing political party already advocates for the movement’s stances and ideologies, there is no need for the movement to form their own party. In this paper, I argue two points that critique this explanation. First, movement parties will form even if political parties advocating for their ideals and stances already exist. Second, multiple movement parties, all of whom advocate for the same ideals and stances, can form at once all within the same political space. By descriptively analyzing the formation of the NPP and SDP I show that political ideologies played a little to no role in the creation of these two parties. What actually mattered was the relationship between movement party founders and pre-existing parties, interpersonal relations within movement party founders, and differences in approach to strategy and tactics. I conclude by suggesting we re-conceptualize the idea of political openings in order to better account for what really matters in movement party formation.