The January 2016 presidential and legislative elections in Taiwan produced a dramatic and unprecedented victory for the Democratic Progressive Party over its long-time rival, the Kuomintang. The party had never had a parliamentary majority before 2016. The elections indicated the potential for fundamental change in Taiwan’s party system. This is what political scientists call a critical realigning election. The problem with identifying these elections, such as the 1896 and 1932 ones in the United States, is that we can only be sure of such an interpretation after a significant amount of time has passed. Still, some of the changes in Taiwan are fundamental enough to make such an evaluation worthwhile. We summarize realigning elections; discuss the factors that may lead to a change in the partisan balance; and describe the growing role of protest parties and social movements in Taiwan politics.