Reading U.S. political commentary online, I’m fascinated by the way candidates and elected officials are referred to by their first names. Gingrich is “Newt,” Romney is “Mitt” or “Willard,” Obama is “Barack” or, sometimes, “Barry.” In Arizona, Brewer is “Jan,” Giffords is “Gabby” and Arpaio is “Sheriff Joe.”

I don’t see this trend in European political commentary (though one exception I’ve...