BERLIN — Recent state elections in Germany have been portrayed as momentous, since the far right finished first in two and may well come to power in one. Yet future historians may focus on another, largely overlooked outcome: For the first time in the post-World War II period, Germany’s Christian Democrats (CDU) failed to pass the 5 percent electoral threshold. Worse, this disastrous result occurred in the largely rural state of Mecklenburg-Vorpommern, where former Chancellor Angela Merkel chaired the CDU’s state branch for close to seven years. Can the CDU avoid the kind of wholesale collapse that other center-right parties have suffered in Western Europe in recent years? History offers some clues. Christian Democracy originated in 19th-century Europe as a movement to protect Catholics from what were perceived as overbearing secular states. Taking their cues from Pope Leo XIII’s Catholic social doctrine, which acknowledged the ills of capitalism while decrying class warfare, the parties associated with the movement were distinguished by their reformist approach to addressing