I wouldn't say "wholesale capitulation", but a few very wealthy people with a lot of money is all it takes.
One thing a lot of people don't understand is that Kamala Harris was making the political pilgrimage to the Silicon Valley all the time when she was in S.F. politics, going to their back-patting events, etc.
But ultimately, her base of support was surprisingly thin, even though she grew up, if not in the belly of the beast, then at least in a popular suburb of it.