It wasn’t that long ago that Taiwan politics gave the term “rough and tumble" a bad name. Sessions of the Legislative Yuan—the island’s main legislative body—could easily be confused with a tag-team wrestling match. Kicking, punching and water fights sometimes shut down the serious business of legislation, prompting disbelief in more “mature” Western democracies like the U.S.

In Taiwan’s current presidential and legislative election campaign, which concludes Saturday, at least the presidential candidates have been loath...