This is the essence of the Democrats' problem. The party decided some time in the 1980s to become a collection of "minorities," as expressed in Jesse Jackson's speech at the 1984 Democrat convention.
The Democrat party leadership must have assumed that the glue that would hold all the groups together would be the adherence to progressive ideology, but that hasn't been the case. Instead, the party has become like a home full of foster children, where the adults keep them around for the welfare they generate--in the analogy, the party leadership keeps the groups around for the votes they generate. The groups are beginning to recognize this, and beginning to angle for their piece of the Presidential pie.
The problem for the party is that there is no such thing as a white/black/Hispanic/dualgendered one-person candidate. Barack Obama was a one-time phenomenon: a person who was able to convince the blacks that he was down for the struggle, single women that he was a feminist, Hispanics that he wasn't a gringo and understood la raza latina, liberals that he was a socialist, and white people that he was the embodiment of King's dream. (That he wink-wink-nudged-nudged that he was a closet Muslim, and never argued against being a closet homosexual, didn't hurt him either.) There will never be another like him, for which we may all thank God.
Going forward, whoever gets picked by the party leadership (and don't kid yourselves, Democrat voters, you will never get to pick your own candidate) will be a trade-off: they will pick a collection of identities that is likely to lose the least number of other-identities' votes, such as picking a Hispanic male who might lose some black votes, or a black female who might lose some white female votes, or a white female who might lose some Hispanic votes. It is the natural result of becoming the party of people judged not by the content of their character but by the color of their skin.
No truer statement has ever been made. And it cuts both ways: the people who are colored as victims are to be put on the government teet, and the white-colored are to be demonized.
This party philosophy in the age of Trump will lead to the Dem's doom as a long term political force -- until they transform themselves and promote America-enriching policies.
I suspect we’ll see more mulattos or mestizos going forward; the problem you describe makes it almost inevitable (in my mind). I certainly don’t see them running two whites in the top slots again, and they’ve already figured they need both genders. Now they’ll need to add a sexual deviant (though they are not big in numbers, they are vocal and have money); from their demonization of white guys who they accuse of single-handedly electing Trump (which they know is impossible), I suspect there will be no outreach to white guys going forward. Fortunately, I believe more blacks and Hispanics know they’ve been played; two months ago they could have elected her and didn’t.