Because nowadays Christian Democratic parties in Europe have become catch-all parties of the center-right, we tend to forget that they once contained a powerful Christian Socialist element.
Suppose for example that Konrad Adenauer had been killed by the Gestapo in the reign of terror that followed the attempt on Hitler's life in 1944. The CDU might have become a different party from the one we know. We think of the CDU as a center-right party devoted to a "social market economy." But in its early years, the CDU contained many Christian Socialists like Jakob Kaiser
https://en.wikipedia.org/wiki/Jakob_Kaiser (Kaiser was closely involved with the participants in the July plot, and was wanted by the Gestapo, but managed to go underground and survive the war).
Kaiser's views are summed up as follows in Dennis L. Bark and David R. Gress, *A History of West Germany, Volume One: From Shadow to Substance 1945-1963* (second edition), p. 114:
"Kaiser's domestic economic policy called for nationalization of heavy industry and worker co-determination in operating business enterprises. He shared the Catholic socialist view that because workers were indispensable to production and had definite interests of their own as a social class, they had a right to exercise those interests in setting the terms of their employment and in enjoying a direct share in the profits resulting from their work. Concerning Germany's position in central Europe, Kaiser saw the new Germany as a bridge between east and west. He believed that a neutral, socialist German government based on Christian principles could mediate between the Soviet Union and the West and help to maintain peace in Europe by reassuring both sides that they had nothing to fear from each other or from Germany.
"In Berlin Jakob Kaiser and Andreas Hermes, both associated with the Catholic trade unions of the Weimar period, led the call in June 1945 for an alliance of all Christian and democratic forces in a Christian Democratic Union. The Soviet Military Administration (SMAD) approved the party, but only in order to bring it under control. Although he fought heroically, Kaiser was unable to prevent the German communist party in the Soviet zone, the SED, from gradually taking away his party's independence. Finally, in 1948, he abandoned the Soviet zone CDU to its inevitable fate and gave his efforts to the democratic CDU in the Western zones. He remained, however, committed to Christian socialist ideas and to a neutral, reunited Germany, which put him permanently at adds with his party leader, Konrad Adenauer."
At the CDU convention in Berlin in June 1946, Kaiser spoke of "the conventional bourgeois social order belonging to a lost generation, an order that will be replaced with an age belonging to working people, by the era of socialist forms of existence...Let us recognize what is needed: socialism has the floor."
https://books.google.com/books?id=7gkUlNqDNm4C&pg=PA209
How likely was it that someone like Kaiser could come out on top in the CDU if there were no Adenauer? Of course he would face the obvious problem that the Americans would prefer someone more conservative, but was there a plausible conservative replacement for Adenauer as of 1945-8 (the years when Adenauer gained control of the party and gradually moved it away from Christian Socialism)? Erhard maybe, but he was disliked by a lot of CDU/CSU activists at first--they thought he was a liberal who would be more at home in the FDP. Indeed, "Erhard enjoyed far better relations with the Bavarian FDP than with the CSU."
http://books.google.com/books?id=nFtkBXw7i38C&pg=PA154 Eventually Erhard's critics were mostly won over, but would they have been without Adenauer?