As I already said, it only took 8 years for Dubya to be seen favourably by half the Democratic base, so there technically is a chance, but the people who decide the Democratic nominee are highly partisan. They are not the apolitical hicks who vote out of habit. The DNC can't tell them who to vote for (fat lot of good it did Clinton in 08), so the daughter of the most repulsive man to them, who has never been involved to party politics, who has never contributed to its candidates, have about as good a shot at making it as me drawing a million dollar lottery tomorrow.
Donald Trump didn't happen overnight. His birther campaign endear him to the deplorables long before his run, and beneath all that abrasive bullshitting tantrums, he aligns with most Republicans on policy issues, or don't care enough to object. He personifies the money is power, might is right dogma that haunt the Republican voting base. Ivanka is not and will never be acceptable in the same way to Democratic voters. If enough people turned up their nose at Clinton, a loyal foot soldier for the party for 40 years, to lose her the election, can you imagine the rift within the party should they run a rich, slave labour exploiting capitalist daughter of the buffoon named Trump, denunciation or no?
It's not about moral, it's tribalism. Glenn Beck spoke out against Trump and did a mea culpa for his Fox day. No one would entertain him as a left wing spokeman. He is part of the other tribe, and so is Ivanka.