TAIPEI • Populism was supposed to be the winning formula. With the ruling Democratic Progressive Party (DPP) steadily campaigning on growing anxiety over threats to Taiwan's national identity, the Kuomintang (KMT), a party that favours close ties with China, risked being consigned to playing permanent opposition. Populism seemed to offer it a way out.

It was populist promises, after all, that had helped the KMT's Mr Han Kuo-yu triumph in local elections and become mayor of Kaohsiung in late 2018.