Opinion journalism is meant to influence and inflame, and it does. Especially in an age in which civics is taught poorly (and, increasingly, rarely), people are politically suggestible. Bill O’Reilly is now the right’s historian, Mark Levin its go-to legal expert, Sean Hannity and Laura Ingraham its moral conscience. These are not ideas guys. They’re anger guys. Their specialty is the communication of rage to an audience prone to histrionics. It can feel awfully good to be awfully mad.

Should it be any wonder that a Republican Party with almost complete control of government has turned so fiercely on itself? Dominant parties often do that when they have little to fear politically from the nominal opposition party.

Should it be any wonder, either, that in the intramural fights the Donald Trumps and Roy Moores of the party are winning? As in economics, so too in G.O.P. politics: Gresham’s law applies. Bad money drives out good. Bad Republicans drive out good ones. When nastiness sells, the worst rise. Political gerrymandering doesn’t help, but that’s a separate column.