The Dems being willing to lose elections rather than meet voter expectations, says more about them than it does any particular voting or non voting group.
https://www.brookings.edu/articles/support-for-israel-contin...
Like a political partys job is to get votes. An electorates job is to withhold votes to punish poor performance. The entity not doing their job here is the party.
The party is aware of the trade-offs. It goes ahead with its best estimation of what will win. Sometimes they can do everything right and still lose. One such scenario is when people would rather have the greater of two evils rather than be responsible for the lesser.
"We can't adopt [potentially winning strategy] because it might harm [definitely non-winning strategy]" is not a reasonable position. You don't have to adopt any specific alternative plan, but clinging to a non-working plan clearly isn't the right answer.