Liaw Yun-fan
Liaw signed a petition in April 2019 calling for William Lai and Tsai Ing-wen , contestants in the 2019 Democratic Progressive Party presidential primary , to join forces and form the party's ticket for the 2020 presidential election . 
<triplet> William Lai <subj> 2019 Democratic Progressive Party presidential primary <obj> participant in <triplet> Tsai Ing-wen <subj> 2019 Democratic Progressive Party presidential primary <obj> candidacy in election <triplet> 2019 Democratic Progressive Party presidential primary <subj> William Lai <obj> candidate <subj> Tsai Ing-wen <obj> candidate