City Journal has an outstanding article on identity politics and how it's affecting our current political debate, with specific reference to the Democratic Party. Here's an excerpt.
Identity politics rejects the model of traditional give-and-take politics, presupposing instead that the most important thing about us is that we are white, black, male, female, straight, gay, and so on. Within the identity-politics world, we do not need to give reasons—identity is its own reason and justification. Because identity politics supposes that we are our identities, politics does not consist in the speech, argument, and persuasion of normal politics but instead, in the calculation of resource redistribution based on identity—what in Democratic parlance is called “social justice.” The irony of identity politics is that it does not see itself as political; it supposes that we live in a post-political age, that social justice can be managed by the state, and that those who oppose identity politics are the ones “being political.” What speech does attend this post-political age consists in shaming those who do not accept the idea of identity politics—as on our college campuses. In the 1960s, college students across the country fought so that repressed ideas would receive a fair hearing. These days, college students fight to repress all ideas except one: identity politics.
. . .
When identity politics provides the lens through which one sees the world, changing the perspective is regarded as self-blinding ... Identity politics can’t self-correct; it can only double-down. Here is the strangeness of our current moment. Untreated, diseases don’t heal; they metastasize.
. . .
Identity pertains not simply to the kind of person that we are. People have been sorted (and self-sorted) into kinds throughout history. Identity is different. First, it carries a determination about guilt or innocence that nothing can appreciably alter. Its guilt is guilt without atonement; its innocence is innocence without fault. No redemption is possible, but only a schema of never-ending debts and payments. Second, this schema is made possible because identity politics is, tacitly or expressly, a relationship—something quite different from sorting (and self-sorting) by kinds. In the identity-politics world, the further your distance from the epicenter of guilt, the more debt points you receive. What is the epicenter of guilt? Being a white male heterosexual. (Throw in “Christian,” and the already-unpayable debt mounts still higher.) The debt points are not real currency, but they offer something that mere money cannot: a sense of moral superiority ... This is the stuff of religion, not normal politics.
Thus, the strange drama of the 2016 presidential campaign: a progressive white woman candidate who promises to double-down on identity politics and who calls those who would chart another course “deplorables.” The righteous white woman gives; nonwhite people and other injured groups, made pure by entering the revival tent of identity politics, receive. Anyone not in on this debt-point dispensation and reception is the wrong kind of white person—Donald Trump and those who voted for him, for instance. They are to be regarded not as mere political opponents but as defendants awaiting the judgment of a religious tribunal.
There's more at the link. Very informative and thought-provoking, and well worth reading in full.
I confess to being very tired of identity politics. I think Robert Heinlein summed it up rather well, in the words of his most famous fictional character, Lazarus Long:
This sad little lizard told me that he was a brontosaurus on his mother's side. I did not laugh; people who boast of ancestry often have little else to sustain them. Humoring them costs nothing and adds to happiness in a world in which happiness is always in short supply.
Unfortunately, the last sentence needs to be deleted for modern readers. Humoring identity politics costs a great deal, and always adds to unhappiness for everyone else.