What the 21st century added to this picture, it’s now blindingly obvious, was media democracy — in a truly revolutionary form. If late-stage political democracy has taken two centuries to ripen, the media equivalent took around two decades, swiftly erasing almost any elite moderation or control of our democratic discourse. The process had its origins in partisan talk radio at the end of the past century. The rise of the internet — an event so swift and pervasive its political effect is only now beginning to be understood — further democratized every source of information, dramatically expanded each outlet’s readership, and gave everyone a platform. All the old barriers to entry — the cost of print and paper and distribution — crumbled.