It might seem unusual that a 16-year-old Taiwanese pop starlet could motivate legions of youth to troop to the polls and vote for the island's opposition party candidate. But she apparently did, and thereby helped Democratic Progressive Party leader Tsai Ing-wen become Taiwan's democratically first elected female leader.

Chou Tzu-yu, popularly known as Tzuyu, is usually pictured prancing, bopping and singing in her South Korean girl band Twice's music videos. But in November, she made an apparently unpremeditated political statement by appearing on South Korean television, holding a Taiwanese national flag.

Mainland Chinese Internet users immediately accused her of advocating formal independence for the self-governing island. Mainland China's government sees Taiwan as a province with no right to a national flag, and has threatened war if it declares formal independence.

After being denounced by a pro-Mainland fellow Taiwanese artist, Tzu-yu made a somber videotaped apology the evening before the election, swapping her usual teenybopper attire for a black turtleneck sweater.

"I have always felt proud to be Chinese," she says, looking chastened and bowing deeply in apology.

While the incident may seem only tangential to the elections, the issue of identity — whether voters see themselves as more Taiwanese or Chinese — remains central to Taiwanese politics, and the defeated Nationalist Party is widely seen to have lost on this issue, and on its failure to appeal to the island's youth.

"I was on a high-speed train from Taipei back to my hometown of Taichung to vote," Taipei-based blogger and e-book editor Wen Li recalls in an interview. "The whole train was packed, and everybody crowded aboard. Many of these passengers may not have intended to return home to vote. But because of this incident, people felt a crisis, they felt 'if I don't vote, maybe I, my family or friends will be the next to have to apologize.' "

Some commentators likened Chou Tzu-yu's apology to a hostage in an Islamic State video. Others blamed her South Korean management company for forcing her to apologize in order not to jeopardize the company's mainland business interests.

Over the past eight years, the ruling Nationalist Party has tried to strengthen trade, tourism and investment links between Taiwan and the mainland in order to jumpstart the island's economy. The political precondition for this policy was a consensus that Taiwan and the mainland are both parts of the same China, while holding different interpretations of who are its legitimate rulers.

"But after eight years, we have found that this is useless," blogger Wen Li laments. "We're still in the same situation, working to exhaustion without reaping any benefits."

"Many people discovered through this [Chou Tzu-yu] incident that what the Nationalist Party said was fake. The Mainland does not recognize our interpretation."

In the spring of 2014, student protesters occupied Taiwan's legislature in opposition to a cross-straits trade pact, in a demonstration dubbed the "Sunflower Revolution."

Tsai Ing-wen does not recognize the "one China" formula, although she also does not advocate provoking China. Mainland media on Monday warned her not to head down a "dead end" of pro-independence policies.

Beijing learned two decades ago that intervening in Taiwanese elections tends to backfire. In 1996, Beijing lobbed missiles into waters off Taiwan's coast, in hopes of scuttling Lee Teng-hui's presidential bid. This only enraged Taiwanese voters, and helped Lee to secure a majority of the vote.

Last week, even pro-government mainland pundits had to agree that the mainland fury over starlet Chou Tzu-yu appears to have boomeranged. Some tried to pin the blame on Tsai Ing-wen.

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