A recent rally in Seoul, South Korea, carried the sound of a rock festival — high-amp speakers throbbing with the K-pop hit "Gangnam Style” — if not the look of one. The crowd of mostly elderly people waved South Korean and American flags to the song’s revised refrain: "Anti-communist style!” When speaker after speaker revved up the crowd with pro-American, anti-communist chants, the crowd shouted, "Hooray for President Yoon Suk Yeol!”​

Days later, when thousands of mostly younger protesters marched through the same city center, they ​shook handheld signs and chanted, "Out with Yoon Suk Yeol!”

Park Yeol, a regular at such rallies, showed up as an inflatable caricature of the South Korean leader. Fellow protesters took selfies while putting him in a headlock.