Germany has long called itself a country that upholds democracy in a “defensive form”—a concept propagated by an establishment that claims the right to decide who and what voters should be allowed to vote for. This principle is now being wielded most aggressively in the fight against the right-populist Alternative for Germany (AfD). This week, a court of appeals confirmed the exclusion of the AfD candidate from the upcoming mayoral election in Ludwigshafen, a western German industrial city of 122,000 residents. When citizens go to the polls on September 21, they will no longer have the option of voting for...