I don't think this is quite right. Harris had rather tepid party support (e.g. as measured by endorsements, especially recently; she had all of 3 endorsements since Labor Day!). It was less tepid than anyone except for Biden's, but Biden's support is *also* on the verge of tepid.
There were a lot of moments where "the party" didn't particularly have Harris's back. She got a some endorsements after her strong June debate, but not a ton, and Biden also continued to get some (despite his poor performance)...
More recently, she was largely ignored by donor types looking for an alternative to the Top 4. In between, she didn't have a lot of surrogates defending her health care plan. Nor, until *today* really, has there been that much talk about the all-white Top 4 & what that means...
In fact, there's an alternative story about party elites being too afraid to intervene in the race because of 2016. That may be changing (see e.g. recent Obama comments, efforts to draft a new candidate). But they haven't been particularly forceful up until now.
