Good principles Democrats have (interpreted to make them as good as possible):
1) Society is capable of lots of improvement.
2) All suffering can and should be avoided.
3) Peaceful differences in ideas or culture should be tolerated.
4) All people matter, even if it's an eight year old blind, lesbian, Muslim girl with purple skin, no money, and no education.
5) When people are unhappy there is a way to solve the problem, so everyone would be happy, without hurting anyone.
It's not obvious to me that Democrats hold to #4 (does Sarah Palin matter? what about gun owners?) or #5 (do they ever suggest ameliorating the unhappiness of poor people in a way that doesn't seem to focus on hurting 'the rich'?).
I think 4 and 5 qualify as improved versions of theories democrats have, which are still recognizable as versions of the less-good theories most democrats actually hold.
The basic problem with number 5 is that some things that make some people happy make others unhappy and vice versa. This is an immutable fact.
Or as Mary Montagu said, "I despise the pleasure of pleasing people that I despise."
I think it's possible to ignore people I despise as long as they aren't hurting anyone.
Also it's possible to reform them, which would make their lives happier.
Sure there are many things that make some people happy and other people unhappy, but that doesn't mean there's no solution that makes everyone happy. (People may have to settle for less or change their desires regarding what will make them 'happy'; it is not static...)
So I do agree with Elliot #5 is a good principle. I just wish Democrats demonstrated more interest in actually applying it than in, for example, expropriation.