SF writer David Brin has been running a multi-part essay on his blog about the conflict of modernism (which he defines "an over-arching dream of ambitiously making a better world through human creativity and will") against romanticism (reverence for stability, the status quo, or even the past). I like his use of those terms, and as a political moderate he rightly criticizes both the Right and the Left for their romantic leanings.
I am, of course, much further to the left than Brin, but I recognize the contrast as well. I think that it is one of the oft-ignored "other axes" to the political specturm. Economics and social issues are the two major axes, of course. There is also the authority-anarchy axis that the libertarians love to point out. But this modernism-romaticism axis I think is a crucial one. Modernism was the essential distilled philosophy of the Enlightenment, and by extention the foundation of American political society.
It used to be that self-described progressives were not only social progressives but scientific progressives; i.e., modernists. Then the Left turned away from science. Scientists now fear reporting even minor discoveries concerning race or gender for fear of accusations of racism and sexism from the Left. The promise of genetic engineering to help provide nutrition for the millions suffering from malnutrition may not be fulfilled because of leftist anti-GM hysteria in Europe.
Conservatives are almost by definition romanticists. However, their suppression of scientific progress ususally comes with a statement about God's intentions or corporate-sponsored propaganda.
In the twenty-first century, with the convergence of the information and biotech revolutions, the divide between modernism and romanticism is going to grow much deeper. You will have romantic liberals (most of the current left), modernist liberals (Hughes's "democratic transhumanists" and technoprogressives), romantic conservatives (most of the current right), and modernist conservatives (the Extropians and classical transhumanists). This doesn't even get into the issue of economic versus social liberalism and conservatism, or globalism versus nationalism. The future is going to be complicated.
But really, when hasn't it been?