Obviously these are fuzzy terms, with different definitions based on who you ask. I would say left and right are two different approaches to the project of smal

Obviously these are fuzzy terms, with different definitions based on who you ask. I would say left and right are two different approaches to the project of small-l liberalism; left wants to move rapidly and make high-risk/high-reward changes, while right wants to move more cautiously and not risk eroding previous wins of stability and liberty. (That's setting aside personality and "moral matrix" differences somewhat, as described by Haidt and Lakoff, and focusing instead on the historical tension between the two political cultures in the context of 20th/21st-century American democracy.) The actual alt-right (exemplified by Richard Spenser, Jared Taylor, etc) are those who stand in opposition to classical liberal principles, even if it's more measured and nuanced than historical ethno-nationalism ("race realism", etc). (As an aside, I've always enjoyed Noam Chomsky's assertion that he's "one of the few real conservatives out there", in his staunch defense of Enlightenment principles, civil liberties, opposition to state violence, etc.) That said, left and right have been drifting apart for the last 20-40 years, and having a harder and harder time finding common ground, as political party identity becomes more salient than American identity. On paper, we agree on certain shared values; yet when one tribe is asked what the other thinks, they're often convinced that the opposing tribe does not share those values whatsoever.