Heading into 2019, Tsai Ing-wen looked at risk of becoming Taiwan's first one-term president. Then came the unrest in Hong Kong.

Tsai had clawed back some ground in opinion polls before protesters started taking to the streets of Hong Kong in the hundreds of thousands in June. But the mass demonstrations there against China's deepening encroachment have given her a noticeable boost ahead of Taiwan's presidential elections in January.

As Taiwanese watch with concern the events in Hong Kong, particularly crackdowns on demonstrators, with scenes of police beating protesters huddled in balls on the floors of Hong Kong's subways, Tsai's firm stance on China has become her biggest selling point.