i've travelled back and forth to Hawaii and currently there now for research related interests.
as far as the population goes, that 40% Caucasian figure is grossly inaccurate. You can get demographic figures directly from the state.http://hawaii.gov/db...able7_share.pdf
pure Caucasians are closer to 1/4th of the population. However most people in Hawaii are mixed and if you include those who are mixed white, then yes they surely do reach 40%. However many people are mixes of more than two ethnic backgrounds. Barack Obama after all is also mixed white and born in Hawaii, and Kelly Hu is another one who is White, Hawaiian and Chinese. Many of the ethnic Hawaiians are usually mixed of something, only in Niihau island is where there are many pure blooded ones as the community there is preserved.
However identity is a totally different issue.. mixed or non mixed, Hawaiian or non Hawaiian, most of the population there identify themselves as "Local" first and definitely distinguish themselves from the rest of the mainland. As whites are a minority and most of the non-Hawaiian ethnicity existed in Hawaii for generations (many of the Chinese, Japanese, Okinawan, and Portuguese groups are already 4th - 6th generation), their identity is more with the island than their place of origin or the US mainland. Within the Hawaiian sovereignty movement, there are many non-Hawaiians as well.
As to why Hawaii became so diverse, the Kingdom was an independent entity before the US came in. One of the reasons why many Hawaiian sovereignty supporters are wary of being classified together with Native American tribes as the Hawaiian Kingdom was in a more advanced stage of development as it already had developed a written language, minted its own currency, had an organized government structure, and developed foreign relations with major countries such as France. Much of Hawaii's modernization drive came from studying British methods and influences, which is why the state flag has a union jack on it.
The Hawaiian Kingdom lasted as long as it did because the French and the British (who were expanding their South Pacific empire) were unwilling to take over Hawaii and provoke some kind of conflict with the other side (a bit similar to Siam's situation being between French Indochina and British India).
However foreigners began migrating to Hawaii, eventually weakening the power of the government and monarchy, and turned it into a giant corporate plantation (introducing pineapple, etc). Initially they used Hawaiians to do the labor, but then brought in Chinese.. who eventually left to do other jobs, Japanese and Okinawans.. who also eventually left to do other jobs, Filipinos, and Portuguese). The Portuguese were interesting case as they were European but engaged in plantation labor. However, controlling Hawaii's economy and supportive of US involvement to protect their business interests were the big 5 families which basically controlled the entire islands turning it into an oligarchy (Castle & Cooke, Alexander & Baldwin, C. Brewer & Co., Amfac and Theo H. Davies). Supporting them were many of the island's Caucasian residents and some of the Chinese residents who began participating in the industries dominated by the big 5.
This is one of the primary reasons why the island is a "Blue State" and heavily supportive of the Democratic Party even before the big political shift in the 70's and 80s which saw many states changing their general party support. Many of the other ethnicities, especially Japanese Hawaiians, ethnic Hawaiians, etc.. came back from WWII and wanted to wrest control away from the hands of a few companies (who were generally pro Republicans). They all joined Hawaii's democratic party and sought change through there.
Now going back to today's time frame, aspects of Hawaiian culture are preserved in the following ways:
Most roads in Hawaii are in Hawaiian.
All grade school students undergo at least a year in basic Hawaiian language. University students have to take a course either in Hawaiian language or something related to Hawaiian history, culture, etc in order to graduate. The courses in Hawaiian history really emphasizes the part of the Big 5 and annexation in Hawaii's history.
All grade school students are able to sing not only the pledge of allegiance, but also the state song which is in Hawaiian, particularly during certain events such as May day where nearly every school students perform the Hula.
There's a strong sense that "local" is better, none of the major US banks could survive in Hawaii, most of the banks are all Hawaii only. Many of the supermarkets are also local except for Safeway. Some of the major fast food chains are able to survive but many of them have items catered to local tastes, and there are many local ones too.
As to whether or not the state can secede from Hawaii.. The main force pushing for this is the Hawaiian sovereignty movement. They are very vocal, and for the most part tolerated as long as they don't violate certain laws. In fact, many of the professors in the Hawaiian studies department at the University of Hawaii are pro-sovereignty. However, most of the population, tends to favor economic interests first. Hawaii is one of the most isolated island chains with a population over 1 million. Honolulu itself is the world's most isolated city under 1 million. As a small isolated island, it has lots of disadvantages if trying to adapt to the global economic system. high transportation costs, limited options in economic development, etc. That's why much of the state's population is employed in the tourism industry, the state government, or directly/indirectly with the US military bases. Separating from the US would probably involve the loss of US military bases, loss of federal subsidies to the state government, and the potential of creating instability which will affect tourism (which also requires state and fed money for infrastructure). Thus, the Hawaiian sovereignty movement, while tolerated and vocal, does not have a majority of the people's support.
Of course those very same industries that employ people create problems too.. i.e. tourism contributing to high land prices, good land being used to build resorts, golf courses and military bases, etc, which could be used to develop local agriculture to offset some of the imported food, etc.
now as far as comparing it to Xinjiang or Tibet.. i believe the only reason people bring this up is because they are either more interested in justifying China's legitimacy over the region, and/or shifting the topic to the criticism of US policies.
however a few points should be made. it is questionable whether groups like the Hawaiian sovereignty movement would be tolerated in the PRC as they could easily be labeled as separatists, nor would there be tolerance to the many professors who criticize the US over their role in Hawaii's history. In fact much of the education of Hawaii's history is generally critical of many things. However there also hasn't been any bombings or mass ethnic attacks between ethnic groups either.. of course there has been some racial issues.. for example the Massie trial in the 1930s in which a white woman accused several "local" Hawaiians of rape (who were local Hawaiians, Chinese, Japanese).. and made the local Hawaiians appeared as savages to the US nation.. only to end up with the accuser being a liar in the end, and the death of one of the innocent suspects by the hands of angry white sailors.http://en.wikipedia....ki/Massie_Trial
for those who are interested in the ability of a state to secede from the US. it should be noted that some territories administered by the US were successful in doing so. Palau, Republic of Marshall Islands and the Federated States of Micronesia for example gained independence from the US administered UN trusteeship in the 80s and 90s. Of course these are not states but territories that the US controlled.