Lose what?
Thanks to Trump, they have exactly one opportunity to court the Reaganites and the Cheneys (and soon the Bushes). The establishment Republicans. This is what the Democrats have been dreaming for decades, and Trump pissing off all these factions have made it possible for the Democrats to seize upon this moment.
Might they be losing voters, yes, but who cares? The donor class is the only class that matters.
Because of Citizens United, prioritizing the donor class means endless funding for future campaigns, while the Republican Party is being relegated to a MAGA culture war party that will soon succumb to its own fracture from internal divisions.