Koo can see Johor changing around him, even if the promised wealth has not reached his bank account. The 30-year-old service worker has lived for 25 years in Skudai, a busy Johor Bahru suburb anchored by universities, older housing estates and the kind of Chinese shoplot economy that helped make the Democratic Action Party (DAP) a force in Malaysia’s southern state. He sees cranes, rail works and projects built by Chinese companies. But before Saturday’s state election, and as the China-linked...