Hong Kong leader John Lee Ka-chiu proved quite the online sensation when he went on Weibo, China’s Twitter-like microblogging site, to condemn United States House Speaker Nancy Pelosi’s visit to Taiwan earlier this month. About 3,000 comments flooded his account in a day, mostly from mainland Chinese across the country, and mostly full of praise. “The tone you now adopt is more like a mainland diplomat – a sign of a closer relationship between us!” gushed internet user “Heiheihei Xiao” from Heilongjiang, China’s northernmost province. The first Hong Kong leader on the mainland’s social media scene, Lee has amassed 1.46...