Su Tseng-chang
On 24 November 2018, he announced his intention to resign from the premiership after the Democratic Progressive Party suffered a major defeat in local elections, and left office on 14 January 2019 after the swearing-in of his successor Su Tseng-chang. Lai mounted a challenge against Tsai in the 2019 Democratic Progressive Party presidential primary and after defeat, served as the running mate of President Tsai Ing-wen in the 2020 Taiwan presidential election in which the tandem was victorious.