“if you try to pin down libs to express their core values they have no idea how to answer.”
I disagree. most liberals I know would quickly say that their core value is to help those in need. As a conservative, I also have that as a core value. What separates liberals from conservatives is not the abstract ends they seek (general human flourishing, minimizing of pain), but the means each believes will lead to those ends. Liberals want to help people by providing for their needs. Conservatives want to help people by helping them become self-sufficient, able to meet their own needs.
You make a good point; however, I think another point of distinction is that liberals define what other people need in terms of what they themselves want, without regard to what the objects of their "affection" really want or need; conservatives, on the other hand, believe that wants and needs are a matter mostly of subjective judgment, and that each person should be left alone to determine his or her own wants and needs, and to design the best means to achieve those ends, within very, very wide boundaries (e.g., no murdering just to get enough money to buy that flashy new porsche you cannot otherwise afford on your service industry wages).
That, of course, is more or less one of the defining differences between socialists-cum-fascists on the one hand and freedom-lovers on the other.