The foundations of modern-day U.S. policy were founded by the New Deal/Great Society. Democrats, within the U.S. context – argue as policy conservatives – they want to retain as much of the status quo as possible, or make changes very gradual. Only the very far left (in active politics anyway) argues for any further expansion of the welfare state.

In contrast, the Republicans have been the ones, at least in the area of economics, setting the agenda and pushing change since at least 1980 (I’d argue they actually succeeded in taking the national zeitgeist even before, in the mid 1970s). Virtually every move in terms of economic/fiscal policy has been a move to their new vision, and away from the traditional conception of American society.

In addition, for the most part social change, which has drifted the U.S. in a leftward fashion, has not been driven by politicians, but by social movements and the media. Elected Democrats only make statements in support of new socially progressive ideas when a clear majority accept them.

Thus he Democrats are moderate conservatives in the Burkean sense, who seek to gradually change economic and social policy to reflect evolving social and economic norms. While I’m not sure that the Republicans could be called policy liberals (except perhaps classical liberals, in some cases on economics), they call for much greater changes in American society (some backwards looking, some ideas never actually tested), making them less conservative and more similar to radicals.

” But what about a very rapidly changing world? Here the logic can become perverse: in a very protean environment it is often best to just stick with what you know, instead of trying to adapt. ”

This makes sense, are there any good examples from biology?

Recent history in the Middle East also seem to validate your thesis.

I think in the United States we may be approaching the breaking points of the positive liberal feedback loop, as the change pushed by liberal activists becomes more and more decoupled from what everyone else has culturally digested (however perhaps only my own biases are talking here). The question is will their be a soft landing, with liberalism merely becoming significantly less ambitious, or is there a chance for cultural “revolution” and subsequent snap back to something more in line with historical norms.

Lberalism, HBD, Population, and Solutions for the Future | JayMan’s Blog

The level of inbreeding likely has an impact on social conservativism (as with the case of Russia and China). Modern day Western liberals do seem to originate from areas where there has been some gradual change (say, between the High Middle Ages to the Renaissance to the Industrial Era), but there does seem to a stronger relationship between recent territorial expansion and conservativism. I’m not sure how much stability is a factor, though I’d guess stability for one generation to the next is important for pioneers.