I don't agree. I see no connection beyond the same words being used. Care to explain how it's the same beyond the words?
I'll try to explain how I see it.
I disagree with this, true identity is often much more fluid and evolving, which is why identity politics (as in, grouping people based on superficial differences) in regards to skin, sex, etc is so flawed, because you can't evolve out of being black or white. There is no culture that comes with having a brain in a coloured or white body.
I'm not sure I understand all of what you're saying, but I think I get it and will try to respond.
true identity is often much more fluid and evolving, which is why identity politics (as in, grouping people based on superficial differences) in regards to skin, sex, etc is so flawed, because you can't evolve out of being black or white.
I agree that identity is fluid, which is why the metaphysical foundations of identity don't make sense. Identity proposes a fixed sense of oneself, which is why gay people insist that being gay isn't a choice--that that is "who they are," so to speak. The metaphysics of identity go back to notions of interiority and selfhood that reveal one's true source of being. Traditionally, this isn't viewed as fluid or shifting, which is why modern identity politics exposes its contradictions when it appeals to identity, since modern identity (what you call "true identity") is all about fluidity. The metaphysics of identity invoke the notion of the insular self, a self that is consistent and unchanging despite external conditions. This is part of the contradictions of identity politics, since it wants to elevate identity at the same time it wants to elevate cultural contingency and social constructionism.
I think you're reversing the issue, saying that identity
is fluid and therefore identity politics is fucked because you can't "evolve out of being black or white." The issue isn't "evolving" out of being a racial, gendered, class, etc. subject though; it has to do with how people classify themselves in any stable and consistent way. For example, individuals of mixed race may not be able to evolve in any individual way out of their biological makeup, but into which category do they fall? Is it selective (in which case we all have the choice when it comes to our identity), or is it obligatory (in which case your identity is entirely contingent on the way people treat you)? The former option is the path of identity politics, which attempts to isolate and elevate a true interior self; and that is what I'm skeptical of.
Now, your comment regarding national identity isn't explicitly proposing a selective attitude, I don't think; but it is proposing that Western culture is non-fluid, or non-fluctuating, since what you're criticizing is the "ghettoizing" of Western culture by outsiders. Basically, you're saying that Western culture shouldn't change, that it shouldn't be inconsistent, that it should stay the same. So from my perspective, you're trying to reify (or stabilize) Western identity in a manner that invokes selectivity; you're saying "This is what Western culture is." And you may be right that, in general, Western culture supports a set of recognizable values and ideals; but calling it a cultural identity insinuates that it's constant and stable, and that external influence might cause it to change and that's a bad thing, when in fact it's been changing for centuries. Even if your position is that it's been evolving and now should stop evolving, you're basically implying that Western culture has finally realized its best possible form, or its "true identity" (which, in contrast to what you said earlier, isn't fluid at all).
Apologies for the length and verbosity of this post-- tl;dr I think that your sense of Western identity contradicts your admission that "true" identity is fluid (and in that sense, not really "identity" at all).