TAIPEI—An emphatic rebuke from Taiwanese voters against China’s authoritarian influence drew disdain in Beijing, prompting some in Taiwan to brace for greater coercive measures from the Communist Party.

Taiwan’s leader, President Tsai Ing-wen, secured re-election on Saturday with 57% of the vote and a record tally of nearly 8.2 million ballots—a resounding endorsement of her pitch to defend the island’s democratic freedoms against encroachment from China, which claims Taiwan as its territory.

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