No one would mistake Mr. Trump for eloquent, but he is a highly effective communicator in a political culture that is now almost indistinguishable from the reality TV culture from which he emerged. But the Trump phenomenon isn’t just about coarsening and stupidity: His political practices are precisely what the founders feared and Lincoln warned against.As we contemplate this, it is worth recalling that the membrane separating what the Scottish novelist John Buchan called “the graces of civilization” from ”the rawness of barbarism” is thinner and more fragile than we sometimes imagine. The reasons for the rise of Mr. Trump are undoubtedly complicated and will be studied for decades to come. That Mr. Trump’s rise has occurred in the Republican Party is painful for those of us who are Republicans. The prospect of turning the party apparatus over to such a person is sickening.'