Summary: Americans once shared a common media landscape, but the rise of personalized digital feeds has splintered that reality into partisan echo chambers. When Walter Cronkite closed his nightly broadcasts with those words, America was a foreign country. Anchors like Cronkite, voted in 1972 by Democrats and Republicans alike as the most trusted man in America, aimed to be impartial and to win bipartisan credibility. Once a social media user spends time looking at political content on one of these platforms, he or she is fed more and more of the same. They simply exploited an information ecosystem already optimized for spreading partisan outrage.