Thinking about what you wrote regarding Hakka cultural identity and ethnic cohesiveness (what I have referred to as ‘Hakka nationalism’), I decided to research this within Chinese language sources. I could not find anything directly relating to Hakka nationalism as such, but I did find this interesting extract:
This translates as:
‘I am not a nationalist, after all, the definition of what it means to be Han is complicated and complex. Han identity has been formulated over a very long time through many periods of turmoil and chaos. Although never officialy recognised, there was extensive intermixing between ethnic Chinese and the foreign invaders that constituted the Yuan and Qing Dynasties. Han is more a broad categorisation of a diverse people now thought to be ‘Chinese’, and is more of a general cultural marker than an ethnicity. The Han ethnicity certainly is not ‘pure’, and may be thought of as very diverse. This is true except in the case of the Hakka people, who althougth a sub-stratum of Han today, are in fact considered to be a unique body of people that preserve and convey a specific type of unsullied ‘Northern’ Chinese culture extant hundreds of years ago. Bear in-mind that the Han are not the only ethnic group that comprises the population of China, even if it is the most populous.’
Later in the same article the author states that following Japan’s invasion of Corea, the Japanese authorities made Corea change its name to ‘Korea’ (within English translation) so that ‘Japan’ would appear before ‘Korea’ when the two names were arranged alphabetically!