Whenever I read about Jewish and black culture, left-wing sentiments often appear. For most Jews and blacks, I think the Republican party is seen as anti-Jewish and anti-black by simply being right-wing in philosophy. If a political party opposes nearly all of your group's philosophy, it seems by definition "anti-" to whatever group you are in. The Republicans argue that their views are the right ones, and that Jews and blacks would benefit more by agreeing with Republican values, but it's still a counteracting force to Jewish and black opinions about where the country should be going.

Capitalism itself isn't very fondly looked at in either culture, while democracy is much more palatable. These sentiments have been developed over hundreds of years of shared experiences. And they aren't just wiped away by simply becoming rich as an individual. Rich blacks mostly still vote Democrat because while they may have "made it," they usually still identify with the experiences of their group's experiences, going back decades or even centuries.  Similarly, Jewish Americans who have lived a good life in America still know the history of Jewish persecution that has occurred throughout history, and their religion itself is apparently more compatible with Democratic values than Republican ones (same goes for Catholics, for example).

Vietnamese Americans are almost entirely made up of refugees (and their US born children) from South Vietnam, as it collapsed to the North Vietnamese government. The Republicans were seen as tougher on Communism than Democrats, so that seems a big reason Vietnamese Americans vote Republican. A similar situation exists with Cuban Americans. Chinese Americans are quite wealthy but vote Democrat, and Chinese have far less anti-Communist sentiments than Vietnamese Americans. A lot of this has to do with the fact that Mao's Communist side was overwhelmingly popular by the time they took over the country. Meanwhile, the Vietnamese war had the nation much more bitterly divided.

So I don't think class and race can be separated, because race and culture can't be separated. Cultures are developed over decades and centuries, influenced by wars, tragedies, successes, etc. Just because Jewish and Chinese Americans are fairly rich today doesn't mean they just throw away history and vote for the benefit of their individual wallets.

    See, the thing is the GOP has spent a lot of time, money, and ink trying to convince anyone who will listen that this is no longer the case. The MSM would be being discourteous to the one thing they do believe in- namely, money, the more the better- if all these efforts were ignored. And with the general election barely living up to the Democratic primary, just about any gaffe that can be shoehorned into a controversy will get at least a trial run.
    The far more interesting thing to ponder IMO is the relationship between Dean and Obama-- or the lack thereof. Dean obviously has different priorities, and you have to wonder if he's thinking that the race issue will help at the congressional level, even if it costs Obama two or three points in the general election, and whether this trade off is worth it. Indeed, a hobbled McCain working (or rather, not working) with Democratic majorities in the legislature might not seem like such a terrible outcome at the DNC and DCCC, if you're being Machiavellian. Every president who runs as an "outsider"* has these kinds of tug-of-wars with the existing party establishment, so this would hardly be unusual-- and is the kind of thing in politics that is far more interesting than elections, at least for some observers. How this all plays out if Obama actually does win will make for interesting, if underreported, theater. May have to put The Hill back in my bookmarks if this happens :)

     *Total geek joke here: in the new D&D system, creatures from other planes (demons, elementals, djinns, etc) are all categorized as Outsiders in the nomenclature. Picturing a presidential candidate as someone who must be summoned by dark magic, and mollified with sacrifices, has a certain amusing quality to me.

Ex ignorantia ad sapientiam; e luce ad tenebras

At the time the US was founded, only land-owners could be considered to be economically successful or respectable; today one could be perfectly successful without owning land, although one should at least own a condominium.  But the basis of the Republican Party does seem to be economic in nature, rather than racial.  They are supposed to protect the interests of the affluent.  Since some African-Americans are also affluent, they may believe that their interests are served by the Republican Party.  There are even homosexuals in the Republican Party, and have their own faction known as "Log Cabin Republicans" although it is, in my opinion, very foolish for any gay person to support an openly anti-gay party.  But again, gay people can also be affluent, and that can influence their political choices.

I would also add that the Republican Party has really made such a mess of things, under the current administration, that it really hasn't served the interests of any Americans, affluent or otherwise, with the exception of a small number of war profiteers.  But they are driving the country to bankruptcy, and affluent Americans are not going to be happy with the result.

As far as I can tell, among non-whites the only groups that prefer Republicans to Democrats are Cubans and Filipinos

Vietnamese-Americans are pretty solidly Republicans.

Illegitimi non carborundum.