I suppose I qualify as a liberal for purposes of this question.
If you're asking whether I'd support this as a political platform, my answer is mostly no.
If you're asking whether I'd support this as a way for the world to be, my answer is mostly yes.
To say that perhaps more clearly...
While I don't think a guaranteed minimum income addresses all problems related to poverty (as sixes_and_sevens points out below), I do think there are a number of poverty-related problems that we currently solve in ways far less sensible than a guaranteed minimum income. If I could wave my magic wand and replace the former with the latter in a politically sustainable way, I probably would. (I haven't looked into this at all carefully and would have to think much harder about the details if I actually had such a wand, but I'm sympathetic to the strategy.)
OTOH, if I don't have a wand, but rather have to work through political mechanisms to implement such a policy change, I doubt I support it... it doesn't seem like a viable political move in my country.
I think it's good to separate out the two problems.
What state do you prefer? What state does it make sense to work to support, given political viability?
Honestly signaling what you prefer allows the possibility of people seeing that you prefer it too. Political viability for what you'd prefer can be increased by signaling that you prefer it.
The last thread didn't fare too badly, I think; let's make it a monthly tradition. (Me, I'm more interested in thinking about real-world policies or philosophies, actual and possible, rather than AI design or physics, and I suspect that many fine, non-mind-killed folks reading LW also are - but might be ashamed to admit it!)
Quoth OrphanWilde:
Let's try to stick to those rules - and maybe make some more if sorely needed.
Oh, and I think that the "Personal is Political" stuff like gender relations, etc also belongs here.