Rauch hones in on the major threats to liberal democracy stemming from political threats to conceptions of fact and truth on which liberal democracy depends, from both the right (commentators, trolls, bots spewing falsehoods that go viral in an instant) and left (political correctness taken too far chills rational discussion). He offers hope that classical liberal notions of fact and truth may yet prevail, pointing to websites like Wikipedia that manage, thanks to an army of editors, fact-based despite the best efforts of trolls. But have we already lost our "herd immunity" to dangerous bullshit?
Rauch makes one very practical suggestion in which I wholeheartedly concur. Next to, or in place of, the "Like" button on FB and Twitter, there should be "True" and "False" buttons.