TAIPEI, Taiwan — Wu’er Kaixi took a microphone beneath a portrait of the Chinese revolutionary Sun Yat-sen and began firing up the crowd around him.

“At critical moments in history, it is honorable to stand up,” he boomed. “At critical moments in history, it is our responsibility to stand up.”

He could have been speaking in Beijing in 1989, when Mr. Wu’er was 21, a student at Beijing Normal University and a prominent leader of the pro-democracy protests in Tiananmen Square.

But this was 25 years later, here in Taipei, and he was addressing student protesters who occupied the Taiwanese Legislature on March 18 to protest plans by President Ma Ying-jeou and the governing Kuomintang to swiftly ratify a trade pact with China.