I'm not convinced that any moral argument is fundamental. What do you want one for? Is that just an "I'd like to see you do better?" challenge? If so, I'm not going to bother, because I doubt it would serve a useful purpose in furthering the conversation, and I don't think anyone was particularly swayed by yours in the first place. Those of us who are already liberals have our own, and those who aren't weren't compelled to change our minds.

If this is a "If I can see an argument for liberalism that is more convincing to an average person not already entrenched in my philosophy, it will change my opinion about my philosophy," then I'll try to provide one, but I'll stipulate that the persuasiveness should be decided by a poll elsewhere, not by either of us. If you can provide a response to my request in my other comment that convinces me that I should continue to be interested in this conversation at all, I would be amenable to that.