Sort of true. Even religious Asian groups like Koreans and Filipinos tend to be Democrats, though. (Koreans are particularly mysterious as they are generally well-off and are mostly evangelicals--Filipinos are mostly Catholics and in general relatively poor.)
Source? I'd always thought that there was a large Republican contingent among Koreans, as well as Taiwanese Chinese, because of the anti-communist posture that those countries historically had. And also among Vietnamese, for similar obvious reasons.
