First, what is "Hapa?"
Samuel Ebert's Hawaiian Dictionary defines it as: of mixed blood, person of mixed blood as in hapa Hawaiʻi, part Hawaiian.
Hapa Haole, means half-White. Hapa Pilipino means half-Filipino. And so forth.
Etymologists trace its roots to a derogatory origin (noted here, and here). Nonetheless, it is widely used by multiracial Asians in North America, and by others describing them. In the current context it commonly is assumed to mean "part-Asian."
I noticed on Tumblr that someone recently changed the descriptor on their blog from "Hapa" to "Hafu." I.e. something akin to "Hapa Life and Times" becoming "Hafu Life and Times." People change their blog titles all the time, and Tumblr is all about warp speed. Furthermore, there have been Native Hawaiian bloggers who, whether on Tumblr or elsewhere have been increasingly strident about reclaiming "their" word. Educators and commentators on multiracial issues like Wei Ming Dariotis have publicly distanced themselves from "Hapa," presumably over this issue.
But is there another reason? Hapa is, of course, a blanket term- the most inclusive term that any multiracial person can adopt (if taken to be defined as "part" or simply "mixed"). Whereas "Hafu" is narrow- it is Katakana (ハーフ) after all, and signals a specifically partial-Japanese identity.
Second, what is the current status of "Hapa?"
I reckon that people might cite Native Hawaiian dissent as a cause for the decline in usage of "Hapa," but I think there is something more fundamental going on.
There are ardent "Hapa" proponents who view "Hafu" as subtly exclusionary. And they are right- it is. But there is a zero-sum aspect to identity- and there always has been. In the Old American South, you were black or white. It was totally binary. You were a believer or a heathen; in or out. No one wants to go back to that stark reality. But the flaw in the concept of "Hapa" remains; in fact it is twofold: (Flaw 1) that you can just add stuff at will (how many times do you hear: "I am Irish, Korean, Lithuanian, Choctaw, and Polish" as a "Hapa" byline), and (Flaw 2) that "Hapas" by default share an identity.
Regarding (1): to affirm all aspects of your heritage is very difficult. I won't say impossible. But it is just very, very rarely achieved when you have unrelated and/or multiple heritages. Could anyone but a champion polyglot master even 3 of those languages? (It is possible- I went to school with a fluent Korean and Polish speaker). In my example, the Polish and Lithuanian backgrounds, are at odds- Lithuania was a client state of Poland for centuries- the animosities and mistrust are well documented. Just the Lithuanian-Polish identity axis merits a decade or two of introspection. What about Choctaw and Korean- as totally unrelated? What ramifications of affirming Korean are their upon the Choctaw sense of self? "Hapas" know that inevitably there are contradictions- everyone will say that. But like anything in life, there is a give and take. Just saying you are "double" or "triple" doesn't cut it with a savvier, Great-recession-hardened generation. Even though you don't have to make binary choices, and there is a lot of room these days for mixed people to shape their identity in many countries- that does not mean you can just keep adding stuff.
Regarding (2): the default shared identity is coming under pressure. "Hapa" tries to smooth the fault lines between ethnic groups. They persist, unfortunately. There are tensions between "Double Minority" "Hapas" and the part-White "Hapas" who some see as reaping White privilege. This is an issue well known to anyone hosting a "Hapa" conference or event. On the other hand, another elephant in the room today is China. Will "Hapas" who are part Japanese or part Vietnamese feel some reservations when they see that China is fast changing so much of the regional order in Asia- to the concern of countries like Japan and Vietnam, and others with similar interests in the South China Sea? Does that flow into perceptions of a part-Chinese person? Maybe, maybe not yet. The tie-that-bound "Hapas" in North America, is under relentless pressure in the globalized world we live in. Many of us may not want to admit it, but Half-Japanese and Half-Chinese "Hapas" can feel the chill happening on the other side of the Pacific- between China and Japan.
Most importantly, "Hapa" is in decline because Gen Z is rising, fast. And they have a different take.
"Hapa" is the ultimate "Millenial" term. It is cheerful. It is "multicultural." It is "here and now."
Generation Z is entrepreneurial, and they want to be experts. They have lived the Great recession; they understand that to get a job they have to think about the future- they need to anticipate where the jobs are going to be, what the challenges and opportunities facing the global economy mean to them. They know that conversational ability in five languages is less valuable than dual fluency. They know that to survive they have to be resourceful- they have to enough foundational skills and knowledge, to be able to learn and adapt as they go, putting them in the position to offer critical cross-functional value. In all of this, they want to be impactful. And any way you slice that- it means global.
My prediction is that a Half-Angolan Half-Chinese Gen Z'er is going to want to know Angola and China. Yes, they will be mixed, and they will deal with contradictions, and complexities- but they will have a supreme interest in being the master of Angola-China, in a dynamic operational-cultural-economic sense. I say dynamic not as a throwaway word, but in the sense that "Ango-Chin" as a unit- actually adapts to changes to both Chinese developments and Angolese ones ("Hapa" is static"). The kicker: they would rather be more and more Angolese and Chinese at the exclusion of a meta, mixed, "Hapa" identity.
With more and more mixed people popping up- the pendulum is going to swing. Just "Hapa" is too abstract, and simply not practical. Mixed is commoditized- people will need to differentiate and the way to do that is to be specific- to go deep. "Hapa" is losing its relevance- but what takes its place is going to be very interesting to see.