Signers of the letter included Anne Applebaum, Margaret Atwood, David Blight, David Brooks, Noam Chomsky, Gerald Early, David Frum, Francis Fukuyama, Todd Gitlin, Anthony Grafton, David Greenberg, Jonathan Haidt, Michael Ignatieff, Gary Kasparov, Mark Lilla, Damon Linker, Dahlia Lithwick, Greil...