Ben Shapiro’s war on Tucker Carlson risks turning conservatism inward—smearing populist concerns as extremism instead of confronting the economic failures driving millions to revolt.Just as a “country without borders is not a country,” so it is that “the conservative movement also requires borders.” This was the general message delivered by conservative political commentator Ben Shapiro in a December 17 speech at the Heritage Foundation and again the next day in a speech at Turning Point USA’s Amerifest conference.Shapiro’s other main point was more specific: Conservative political commentator Tucker Carlson is no conservative and must forthwith be expelled from the conservative...