China and Taiwan have been separately ruled since 1949, but Beijing still claims sovereignty over the island and occasionally threatens use of force to take it, if needed. A Taiwan government public opinion survey in January showed that most Taiwanese prefer self-rule.

In November, Han was elected mayor of the port city of Kaohsiung, a traditional ruling party stronghold, largely by pledging to improve the local economy. A rising star, he is a charismatic speaker who often appears with his blue shirt sleeves rolled halfway up.

“Han mobilized the middle class and the lower middle class without paying money,” said Joanna Lei, CEO of the Taiwan-based Chunghua 21st Century Think Tank. Over the past 12 years of Nationalist leaders, she said, “Han Kuo-yu is the only candidate who has a really strong appeal to the lower middle-class voters.”

Tsai has vociferously stood up to China since taking office in 2016 and particularly since Chinese President Xi Jinping advocated earlier this year that China govern Taiwan under the same “one country, two systems” setup as it rules Hong Kong. Millions of Hong Kong citizens have protested in the streets since June against elements of Chinese rule.