Generalizations about Asian voters, in particular those that ascribe voting behavior to a cultural value, are hard to support across multiple nationalities. There's little that South Asian and, say, Chinese immigrants have in common. What the American-born generation largely shares with their parents is an appreciation for diversity and belonging to the U.S. When the Republicans talk about Real America and how great things were before modern immigration, even if you were born and raised in the U.S. and identify fully as American, it's going to alienate you.
I think this is the most on-point characterization of Asian-Americans in this thread. If you must generalize about Asian-Americans, the one thing that unites nearly everyone* from Chinese-Americans to Cambodian-Americans and Asian parents to ABC's is that we get pissed off when we get the sense that we are considered perpetual foreigners or not Real Americans. With the exception of older Vietnamese Americans (war refugees), most Asian-Americans are in America by self-selection (or are first gen, like me) and don't take too kindly to the implicit notion that we don't belong.
Stuff like Pete Hoekstra's ad and that Chinese Professor ad made big headlines within the Asian American community. At least with younger Asian-Americans, we notice things like the GOP's anti-immigrant rhetoric and the Kenya/birth certificate nonsense and can smell the racist tinges behind those words, even if not directly aimed at us. And finally, the GOP really doesn't know how to talk to minorities, period. Remember the post-2008 argument by Republicans that Obama's win was because of white guilt? It totally removed all sense of agency from the non-white members of the Democratic coalition. Or the current idea that the GOP can maintain decent electoral performance by picking up on "missing whites". Just a few of many examples where Asian-Americans (and probably other minorities as well) get the sense that the GOP does not care about them.
I would also add that Asian-Americans on the whole are ideologically far more liberal and less conservative than other racial groups in America; the idea that family values or social conservatism would tie them to Republicans is a silly and superficial way of looking at it.
As for some of the other theories postulated in this thread, I'm not comfortable generalizing about them to speak for the Asian-American community as a whole; most Asian-Americans really care about educational issues for sure, but between Indian-Americans (70% with a bachelor's degree) and Cambodian/Lao/Hmong-Americans (~12% with a bachelor's degree) there's a lot of intragroup variation that makes issues like affirmative action tricky. The "Asians have more respect for civil service" claim also suffers from oversimplification; for every Chinese immigrant who grew up in a bureaucratic-revering, Confucian society there is a Filipino or Syrian-American who escaped from a dictatorship and wants the government to get the hell out of their business...or a first gen like me who grew up reading Locke and Nietzsche. And don't get me started on the "Asians are more collectivist!" argument...let's not make David Brooks-esque arguments here, guys.
tl;dr version: Asian-Americans are strongly turned off by racist Republican rhetoric that drive them closer to a Democratic party that they ideologically lean towards anyway, but the inherent issues with generalizing about a group so broadly defined as Asian-Americans make it hard to explain why. Hence why we get a hot article every year or so asking "Why are Asian-Americans so Democratic?"
* we have our share of twinkies, no doubt.
