In a slave economy, slave owners seek technological innovations that make slave labor more productive. But they also place inefficient and artificial limits on innovations that might change the established social order.
Because the rich generally save and invest more of their income than the less wealthy, they are the primary builders of the pool of available capital. Taxing away their incomes means less capital for everyone.
Although many Americans often conflate the two ideologies, conservatism and (classical) liberalism are historically quite distinct. Indeed, conservatism has long been explicitly hostile to both capitalism and classical liberalism.
The trial of Julian Assange will have consequences that are far larger than the man himself. Whatever will be Assange's future, he is already one more martyr in the historic struggle for political freedom from which everyone can take inspiration.