Tucker Carlson, the top-rated Fox News host who has built a following pushing conspiracy theories and lighting into the culture wars, on Friday flirted with a presidential run in his speech to a large gathering of Christian conservative voters in Des Moines, Iowa. Carlson used the event to blast transgender athletes, high energy prices (and wind turbines), make a glancing mention to Jan. 6 (an issue which hasn’t engaged voters on the right), before ultimately pivoting to an attack on corporate America. The speech ultimately focused on the kind of pocketbook issues that have been engaging many voters this year,...