She's a non-white woman. That's enough of an obstacle.
Pretty sure that’s her biggest strength in the primary. Literally can’t hear any of her supporters talk about her without going ‘on ya, and did you know she’s a black woman??’ I doubt it would be a detriment in the general in states Dems will compete in either.
Kamala Harris’ biggest problem is twofold and interconnected: she’s a California liberal. This is twofold because not only is she pretty far left and has an ill-defined economic message at this juncture (with California’s economic struggles and general insanity on full display in the background), but she also can be attacked as being a Pelosi puppet because she’s from Pelosi’s backyard. The ads practically write themselves. The best thing for Harris’ presidency would be an upswing for California combined with clearly defined views and a platform that emphasizes her strengths and talents / knowledge beyond the standard party line and especially beyond of even contrary to what Pelosi or the stereotypical San Francisco (I know Harris is from LA but if Conor Lamb gets branded as a San Francisco liberal you know she sure as hell will too) would believe in.
I really think that Dems need someone from the middle of the country who can speak to people there. Obama being from Illinois helped immensely in that regard - he understood the center of the country to some extent, or at least did a good job of saying he did. Cali and New York don’t need to be the center of the universe for Dems.
While I agree, the Democrats could run Doug Jones or Jon Tester and would still get attacked as the party of 'Liberal San Franisco' values. So it's really a lost cause deciding who to run based on who the republicans will attack.
Doug Jones or Jon Tester could counter those claims by talking about how they're from the heartland, how they believe Democrats need to represent the working class, etc. Harris can't, since she's from a state hated in the heartland.